Sohl

Viral Invaders? Maybe not... Stay tuned!

Short update: Made cell membrane match the Tissue foreground color in both Intra and Exo play modes (tying things together nicer) as well as the tissue "bumps" in the Intra screen above the cell membrane.

Some recent development: After spending way too much time to make a dark background around the status area icons left of the status bars in Exo mode (so I could have a all-deep-red status area background color as mentioned upthread), I decided it did not look good, so I went instead with a pink color for the upper portion of the score/status area, and have that background color fade into a deep red. Having a relatively light background color behind the virus load icon helps the virus icon with its deep red spikes still be discernable. I may still adjust these colors a bit more, but I'm happier now with this design artistically. Feb. 8-15 Changes: * Health penalties for disrupting RNA and virus escape increased to 4 and 5, respectively * Random choice for next energy/vitamin molecule made more likely to alternate (prior code often had long streaks of same type) * Tweaked vitamin sprite; made vRNA sprites thicker horizontally so they show up better on TV * Pink-to-ruddy-red fade of background color in score area; made color of score digits and score icons darker to contrast with pinkish background Additions: * Added black heart and -4 sprites that display in quick succession for disrupting vRNA fx if you don't have any vitamins and will therefore have a health penalty Fixes for... * Vitamin collect animation pulling in wrong sprite data * vRNA disruption fx should depend on scoring, which is based on vitamin level. I still want to implement the basic scoring/penalty review intermission displays I mentioned upthread before I release a new version of the demo ROM. Stay tuned!

Yes, me too! I started mostly with magazines (which were pretty affordable back then) and books from the library or Radio Shack or full bookstore. I got the Atari 2600 BASIC cartridge but quickly exhausted the limits of that. A bit later my parents bought the family a TRS-80 Color Computer (CoCo 1), and in a couple more years, a C64. The CoCo and C64 had pretty good manuals, especially the C64 if you bought the Programmers manual.

I appreciate the compliment. Yes, for the "intracellular" play mode, that would be a lot of blue if I went with the blue score background! The more I think about it, I do like the idea at least of the deep red background, but to make that work, I'll need to adjust the colors of some other score/status things I think to make it all look decent, such as using white for the breaths count and maybe the status bars so I don't have yellow against red. I'd probably also need to put another color behind the status bar icons so that the virus icon with red spikes is recognizable.

I have thought about having some user-configurability, but this takes at least a little RAM and I'm not done implementing all the main features yet, so I need to see where I will stand later on. My comment about using a second joystick to switch & test colors was just in context of a temporary development step, but I suppose I could try to leave it as a feature I could bring back if I determine I can fit everything in. I've not thought about HS saves... I don't even know how to do this currently. I've been developing this game as if it was an old-time 16 KB ROM with F6 bank switching. I'm aware of other expanded formats with extra RAM, and I suppose some modern carts have persistent storage features. It would be cool to be able to store and retrieve settings, I do admit.

I'm trying out some different colors. Here's a range of background colors for the upper score area. The dark red is good from a biological theme perspective, but some things won't stand out as well (the virus icon for the status bar, not shown here). Black is good for hiding HMOVE bars and high contrast, of course. I like the blue for contrast too, but maybe weird for the game's theme, as is the mossy green. The bottom one is a very dark brown. It's not too bad for contrast and could be a plausible skin/hair color, but I'm not committed to it yet. These examples are captured from my instance of Stella emulator with these settings: You can also see one of the sprite changes I'm trying out: The viral RNA has been made thicker for better visibility. The cytoplasm has been made another notch darker, but I'm not sure I like it (at least in Stella). It's making the loose spike protein harder to see. I'm using these video settings in Stella: Maybe I will make special ROM build where I can use the other joystick to dink the colors around and see how they work together on a real CRT TV. Unfortunately, however, I think my 40+ year old 2600 console is not outputting as clean and bright of a video signal as it should. Perhaps I need to adjust a trim pot in the 2600 video circuitry or replace some capacitors? I've not attempted that yet. I'm sort of handy with electronics but I'm much more of a software guy than hardware. What are your thoughts?

Pinging @Arenafoot and @ZeroPage Homebrew for their extensive knowledge!

I've been busy 'under the hood' of Immunity to free up space to add new features. This mostly entailed moving some drawing kernel code with the supporting subroutines and constant data tables into Bank 3 from Bank 0 and Bank 1. It was kind of tedious to re-order the constant data tables to pack together and align nicely in the new bank arrangements, but now I have much more space in Bank 0 and Bank 1, which will allow me to add the new significant features I mentioned above. I had some code regressions, of course, doing all of this. Besides getting the new bank-switching jumps correct and not causing timing issues, I also had a pair of bugs with the same root cause: I had a few strobes to the HMCLR register (sta HMCLR) that were set up to occur some period of time after strobing HMOVE, as proscribed in the 2600 programming manual. However, when I reorganized things, code that was contributing to the needed delays were moved, so the delay before HMCLR was no longer sufficient. I saw sprites that looked sliced-up where each row was at a progressively skewed but disjoint position, and a missile graphic stretched or repeated on a row. I just needed to put in some time-wasting subroutines to provide the needed delay before HMCLR is strobed. Maybe layer I'll find a new location in the code to strobe HMCLR so I don't need to have the artificial delays and regain those few bytes. I also fixed a potential game-over issue: in the "intracellular" gameplay, when you disrupt the injecting viral RNA, you will loose health. If your health drops to zero, it should be game-over! However, in recent releases, I don't think it has been working this way. The game lets you continue until the intracellular mode is done, at which time you might get health bonus that allows you to keep playing in the exocellular mode. Now if you drop to 0 percent health, it is an immediate game-over event. I'm not posting a new demo release yet. I'd like to add at least one player-obvious new feature first. Have you voted in the 4th Annual Atari Homebrew Awards yet?

I updated my prior post with a few updates including some modest bug fixes, which I made available in a revised .bin. Scroll back to get the latest!

I like the top center column and middle right column barricades (fences). I also very much like these traffic cones.

I'd like to share a new version of the demo. TL;DR: New status displays in the "intracellular" mode; slight updates to colors and virus sprites. Summary of changes and additions: The vitamin and energy levels in the intracellular mode are now displayed just below the Health percent and Breath count numbers, replacing the Viral Load bar (more to come on that). The amount of new antibodies created from collected spike proteins is shown at the screen bottom (the endoplasmic reticulum region) as a yellow or green bar that expands from the center, one increment per two new antibodies. Color indicates how close to fully "topped up" you will be with antibodies when you switch to exocellular mode, green for within 8 antibodies of the max, yellow otherwise. In intracellular mode, the top Antibodies supply bar is now muted in color (more to come there too). Virus sprites, both dual-sprite version and one sprite version (with alternating color rows), have been tweaked in appearance, mostly to make them "more spikey". Injecting viral RNA speed range is more limited and does not allow the slowest speeds in the January demo. Right now the vRNA speed is not difficulty-adjusted, but I plan to do this. Special Effects/Sound was re-engineered under the hood to use less RAM. Some events share the same count-down variable and can preempt each other, others are have independent counters and can be managed simultaneously, although only one associated sound for an event will be heard at a time. Some code refactoring to remove redundancy. Fixes: Several more minor color adjustments for hopefully better contrast in both play modes. Fixed screen linecount issues on title/game-over screens Used Developer Settings to find some bad initializations such as forgetting # on a load instruction* for an immediate constant (and not some random memory location) as well as assuming undocumented hardware register bits are always zeros. I don't want to admit or think about how much time I spent troubleshooting a game object positioning issue before I re-read Andrew Davie's "Newbie" Session 22 (part 1) that is about sprite X positioning and from which I realized I had a positioning loop that was crossing a page boundary* in at least one instance that was throwing off the timing and therefore the location of the RESP0 strobes. I think it would be good to find or create some macros to keep these critical sections of code or data tables that should not cross page boundaries intact by automatically doing selective alignment to page boundaries. * Even us seasoned programmers goof up sometimes! Disclaimers: For speed of testing/debugging while I work on feature additions/changes, I usually play at Beginner difficulty; consequently, advanced difficulty is much less tested and could be buggier or at least less refined/balanced; I'll do more testing in advanced mode as the feature set solidifies. There is a bug in exocellular mode where if you hit a virus with an antibody and a second virus is also visible, sometimes (but not always) both will get hit and have spikes neutralized. ... Consider this a temporary power-up! (maybe I'll come up with an intentional power-up scheme ) FIXED (? I think?) in Feb1b .bin UPDATE: Free Ribosome speed bug... Energy level 4 is not the fastest, its the same as level 2. FIXED in Feb1b .bin UPDATE: 'Disappearing neutralized virus' when close to cell and Macrophage is active. FIXED in Feb1b .bin To-Do (at least I very much want to implement and offer...) Bug fixing (of course)! Screen-switching status update "intermissions" that will recap what happened in the just completed screen in a hopefully engaging way Basic two-player game mode. Plan out some cool benefits for the potential retail version compared to he demo, besides removal of "DEMO" appellation As always, I enjoy your feedback and will consider any issue reports or suggestions. immunity_2022_Feb_1b.bin

In Stella's TV Options, there is a phosphor setting. If you make it higher, it helps persist some of the prior frame, but perhaps there's a more direct way to combine even and odd frames.

Ooh, these are pretty good. If the sprite can be animated over several frames, you could even combine the first or second with the third, and have the worker "appear" to walk out from behind a building, jackhammer a bit then walk off. I mocked it up in SprEd... 2022-01-30-19-20-21.mp4 ConstructionSprites.bas ConstructionSprites.asm

I think that it could be as simple as a temporary blockage that appears randomly from time to time (not always on screen) between two buildings so that it blocks vertical movement. That would be a lot easier to implement than a place to block horizontal movement because it would conflict with drawing the cars/taxis. Concept Sprite for traffic cones (mocked up in SprEd at https://bocianu.gitlab.io/spred/ ). This needs to have the player color changed for certain rows if you want to have the white reflector portions. They could be all orange (single color).

@kid_snz Sure, that short program is completely unrestricted, so you (and any collaborators you work with) are welcome to use as much or little of it as you want! It shouldn't be too hard to implement the honk sounds using the TIA register setting numbers in other languages or styles of programming. The sound volume envelope stuff could be omitted without changing the sound impression much. The Whistle sound is more dynamic (although the effect is sort of subtle), so it may need to be done in assembler... although I'm not familiar whether the BASIC tools could handle it too. All: I forgot to put the controls instructions in my last post, but if you didn't peek at the source code, all the different sounds are activated by: ; Left joystick ; Left: Car Horn 1 ; Right: Car Horn 2 - lower pitch ; Up: Police whistle ; Dn: Jackhammer ; Fire: Whoosh (as car goes by?)

Updates and more sound effects: I improved the police whistle sound, but it is still not as good as I hoped. I added a jackhammer sound. I didn't work on it too long, but I think it gets the idea across. I added a "whoosh" sound that might be used for cars going by. I think I fixed the display linecount issues, at least the major ones. I'll post the full .asm source code in case someone wants to "borrow" any/all of these sounds. I need get back to working on my Immunity (game). SohlSounds_Jan28.bin SohlSounds.asm

Thank you!. I 'm glad you like them. I want to make a second try at the police whistle sound... if I come up with something better for it, I will post it soon. Maybe there could be road-construction jack-hammer sounds and car whooshing sounds too! Hmm. Road construction could be a good obstacle in the game. For the programmers, the count-down variables Honk1Cnt and Honk2Cnt get initialized to #32 in the joystick check part of the Overscan processing routine. Then, in the sound-playing code in the VBlank routine, the count-down timers are checked to see if a sound is active, and if so, the count decremented and then used to fetch the proper sound volume setting for the current time-step. The frequency and tone type is fixed (not modulated). I thought about trying a doppler-shift effect, but the Atari TIA chip does not have enough frequency resolution to do the proper slide down in frequency. If both countdown timers are non-zero, Honk1 will be processed first (Honk2 code is skipped when Honk1 is active), and when complete, Honk2 will start immediately. Code excerpts, in assembler (hopefully not hard to do bB if that's being used): He lda Honk1Cnt beq .honk1.done Honk1Snd: dec Honk1Cnt beq .honk1.done ldy Honk1Cnt lda HonkVolEnvlp,y tay ; vol ldx #12 ; freq - about 403 Hz - Note ~ G4 lda #12 ; tone sta WSYNC ; #3 sty AUDV0 stx AUDF0 sta AUDC0 ldx #10 ; freq - about 476 Hz - Note ~ A#4 sty AUDV1 stx AUDF1 sta AUDC1 jmp .sndDone .honk1.done: sta WSYNC ; #3 lda Honk2Cnt beq .honk2.done Honk2Snd: dec Honk2Cnt beq .honk2.done ldy Honk2Cnt lda HonkVolEnvlp,y tay ; vol ldx #15 ; freq - about 328 Hz - Note ~ E4 lda #12 ; tone sta WSYNC ; #3 sty AUDV0 stx AUDF0 sta AUDC0 ldx #13 ; freq - about 374 Hz - Note ~ F#4 sty AUDV1 stx AUDF1 sta AUDC1 jmp .sndDone .honk2.done: sta WSYNC ; #3 Data tables for the sound envelope (volume over time... can make the sound ramp up over time and/or fade more or less over time) ; NOTE: This table will read back-to-front since it is indexed by a count-down variable HonkVolEnvlp: .byte $09, $09, $09, $09 .byte $0B, $0B, $0B, $0B .byte $0E, $0E, $0E, $0E .byte $0F, $0F, $0F, $0F .byte $0F, $0F, $0F, $0F .byte $0F, $0F, $0F, $0F .byte $0E, $0E, $0E, $0E .byte $0D, $0D, $0D, $0C

Here is a binary of the sound experiments I did for a car horn and a police whistle. The screen will stay black the whole time and there are some +/- 1 screen linecount issues. To hear a sample sound, use the left joystick, and move it: Left to hear a basic car horn Right to hear a lower-pitched car horn Up to hear a (bad) police whistle I'm using both TIA sound voices simultaneously to get the sort-of-clashing dual fundamental frequency audio spectrum of typical modern car horns. I'm doing something similar for the police whistle, but for that I'm keeping one voice pitch constant, while the other is modulated by the countdown variable and table lookups to determine frequency. If these sounds are not playing, the game could play other sounds such as the theme music or other kinds of background noise. SohlSounds.bin

This sound wiki has several examples of police/referee whistles. Here's one: https://soundeffects.fandom.com/wiki/Folkways_Records,_Police_Whistle Also has car horn beep/honks: https://soundeffects.fandom.com/wiki/Valentino_Car_Horn_02 ; https://soundeffects.fandom.com/wiki/Hollywoodedge,_Car_Horn_Honk_Close_Mi_CT052301 We could use these examples as reference as we try to make similar sounds with the TIA. I suppose someone could get fancy and download/capture the sound waveform and analyze it to get the frequencies and amount and rate of modulation (e.g. the "pea whistle" used by many police and referees is primarily at 2600 to 2800 Hz according to online info, but changes in volume, and perhaps pitch slightly, as the "pea" inside the whistle rolls around, passing the opening at several Hz). Maybe I can work up a prototype sometime soon, but not tonight! Thanks for the kind words about my unfinished game.

To add to the city feel, how about a police whistle sound (e.g. that police use when directing traffic) at random times or correlated somehow with the taxicabs?

I'm honored to be Nominated for a WIP 2021 Atari Homebrew Award. My competition is truly awesome! The demo version I had ready at the end of 2021 was still quite a mess. Some of the other nominees are much closer to a final version. https://atariage.com/forums/forum/203-atari-homebrew-awards/ (main page) 2600 WIP (Original) award category: Downloads of ALL eight nominees in this category are here: https://onedrive.live.com/?authkey=!ALk2LM2cMybD8Bc&id=EBF48A1964E7EEB5!3387&cid=EBF48A1964E7EEB5 Try them all and vote for your favorite!

It's been a long day and evening, but I have Immunity running fairly well with the main changes I outlined above and some additional details I had planned out. I will paste the contents of a partial and early draft of the manual, but also include it formatted in a .pdf, along with the playable demo .bin, of course. I hope you enjoy this version better than the Dec. 31 version... it has a lot fewer bugs and illogical play mechanics. This new version is much closer to my vision. I expect to continue to polish the gameplay, especially the controls and tuning of special constants that affect the gameplay balance (initial inventory levels and size of infection rounds, etc.). I will also work on some of he longer-term features I outlined above. My first three ROM banks don't have a lot of room left, but the last bank has about 3.5K, so plenty of space I think for the new things I listed above. Please provide your feedback on what you find too easy/hard, what you like and not like so much, as well as anything that seems like a bug. Don't forget to try the left difficulty switch! IMMUNITY Atari 2600 Game by Michael Losh (AKA mike_sohl) Gameplay, Rules, and Scoring (Disclaimer: Intended functionality... almost all implemented, but not guaranteed bug-free yet) Game Overall Health starts at 96 percent, max health is 99% (100 not allowed) Gameplay starts in the Intracellular mode screen Game ends in Death if Health reaches 0 Game ends in Death if Antibodies reaches 0 with unkilled viruses present/available Game ends in Immunity if Viral Load reaches 0 with at least one Antibody available Viral load is the number of available viruses that can attack and latch onto cells, may be visible or waiting off-screen Breath count in status area indicates how long the player managed to survive or how quickly Immunity is won Game difficulty is controlled by the Left Difficulty Switch. Game Overall -- Easy/Beginner Difficulty Viral load starts at 9 Antibody supply starts at 12 Vitamin Molecules, Energy Molecules, vRNA, and free Viruses in/out of cell move slower generally Game Overall -- Hard/Advanced Difficulty Viral load starts at 15 Antibody supply starts at 6 Vitamin Molecules, Energy Molecules, vRNA, and free Viruses in/out of cell move faster generally Intracellular play mode (action inside cell) Screen ends when there are no more available vRNA strands, implanted vRNA has all expired, and all free viruses have been killed or escaped; when screen ends, it switches to Exocellular mode screen Screen always(?) has three latched viruses at the top (not counted as part of Viral Load) Player controls the Free Ribosome up/down along the left or right edge of playfield Player can shoot the Free Ribosome rightward or leftward through the cytoplasm across the screen Pressing fire will "scrunch" the ribosome to get ready to shoot, while releasing the fire button will let the ribosome go Moving the joystick while Free Ribosome is shooting will not affect its direction Free Ribosome shooting speed is based on Energy Level 0 to 4, with higher levels being faster When there are no infection or 'good' objects up high near the outer cell membrane, the Free Ribosome can "bump" the outer cell membrane by player moving it up to the membrane and hitting "fire" in very close synchronization to the time it reaches the top position at the membrane. If successfully bumped, the membrane moves and latched viruses stretch and cytoplasm color goes white for a moment and then a batch of spike proteins shaken free from a latched virus will appear in the cytoplasm. The batch of loose spike proteins will include 1 to 4 particles according to Energy Level of (1 to 4) The Free Ribosome can collect Vitamin Molecules by touching them (while shooting or along side) When close to a Vitamin or loose spike protein batch, Free Ribosome will open into a "chomping" pose (As a consequence of the graphics kernel's use of drawing objects), the main portion of the Free Ribosome's color will match the color of the current "Good" object, which may be a Vitamin Molecule, Energy Molecule, or Loose Spike Protein batch Killing each vRNA strand or a free virus expends 1 Vitamin Level, reduces Health percent by 2 Killing each free virus when the Vitamin Level is low (depending on difficulty) may reduce Energy Level by 1 (depending on current energy level and difficulty) Killing a free virus will cause the Free Ribosome to bounce backwards from the collision Killing each free virus will loosen 1 to 4 spike proteins in a batch according to Energy Level 1 to 4 that can be collected Loose spike proteins have 1 to 4 pieces and will add that many Antibodies if collected, up to the limit (32 antibodies) Each virus that escapes adds to the Viral Load and decreases Health by 3 percent Up to three vRNA strands can be implanted on the Endoplasmic Reticulum (E.R.) at a time, when a vRNA strand expires, its space opens again for other vRNA strands to implant there if any are available Up to 4 Vitamin Molecules can be collected (additional collection of vitamins objects will not increase tally) An Energy Molecule must touch the Mitochondria in the lower sides of the playfield to be absorbed and raise the Energy Level, which may be from 0 (adv. difficulty only) to 4. Additional Energy Molecules touching Mitochondria will not increase tally. While some Energy Molecules may drift into the mitochondria passively, the Free Ribosome may bounce the Energy Molecule into a better vertical position to be absorbed; bouncing occurs when the Free Ribosome touches the Energy Molecule Each implanted vRNA strand can grow multiple copies of new viruses Health bonus of 3 percent per Vitamin Level at end of Intracellular screen Health bonus of 3 percent per Energy Level at end of Intracellular screen Intracellular -- Easy/Beginner Difficult Infecting vRNA strand count starts at 8 for each Intracellular screen After implanting, each vRNA strand will produce 4 viruses before expiring Energy level cannot drop below 1 Bouncing Energy Molecule with the Free Ribosome will always send the Energy Molecule downward Energy molecule random initial position generally lower on screen (closer to mitochondria) Intracellular -- Hard/Advanced Difficulty vRNA strand count starts at 12 for each intracellular screen After implanting, vRNA will produce 6 viruses before expiring Energy level can drop to 0, which is too low to kill vRNA and free viruses (Free Ribosome will bounce off) Bouncing Energy Molecule with the Free Ribosome may send the Energy Molecule upward, sideways or downward depending on the relative vertical position of the Free Ribosome and Energy Molecule Energy molecule random initial position generally higher on screen (farther from mitochondria) Exocellular play mode (action outside cell) Screen ends when all tissue viruses have been neutralized or latch, or when three viruses have latched Player controls Bound Ribosome that can move horizontally along the E.R. Player may fling Antibodies from Bound Ribosome by pressing Fire button; press causes the ribosome to scrunch up in preparation of the firing while releasing the fire button actually flings the Antibody upward Antibody speed is fast if the Antibody does not hit the cell membrane or solid parts of tissue and very slow after it does hit something Player may not fling another Antibody while prior Antibody is still moving, so aim carefully! When antibody hits attacking virus, it covers & neutralizes 1 to 3 rows of the spike protein depending on the vertical position of the virus when hit (higher hits cover three rows of spikes, low hits cover one row, intermediate hits cover two rows; covered rows of spikes take on a yellow color (versus red normally) When a virus has all of its spikes neutralized (appearing yellow), the player can switch control to an external Macrophage by pressing upward on the joystick; player can switch back to controlling the Bound Ribosome by pressing downward on the joystick. The macrophage will "chomp" when moved left/right by the joystick in the tissue but will be vertically positioned alignment with the lowest fully-neutralized virus; when the neutralized virus is fully engulfed by the macrophage, the player may press the fire button to dissolve (and kill) the virus Cell membrane normally has three open pores but the size of them will vary in a cyclic manner during normal "respiration" When at least one virus latches to the cell membrane, the center membrane pore closes up, and the left & right pores will twitch a small amount, reflecting the cell's "shocked" state Heath bonus of 10 percent for clearing a tissue screen with NO latched viruses Health penalty of 5 percent for each latched virus (up to three per screen) Health penalty of 5 percent per unkilled virus (either latched, free at end of screen, or still available) at end of screen (No antibody bonus for clearing a level now as in earlier releases) Exocellular -- Easy/Beginner Difficulty Per-Tissue attacking virus count set to 6 Attacking virus speed slower, generally Exocellular -- Hard/Advanced Difficulty Per-Tissue attacking virus count set to 9 Attacking virus speed faster, generally Immunity_Initial_Manual.pdf Immunity_2022Jan18.bin

Development update: I've been working away to refine Immunity, squashing many bugs and issues that were apparent in the recent ZPH play-through (thanks @ZeroPage Homebrew James and Tanya!) or to me though my own testing. For now, the changes have barely impacted the visual appearance of the game, but I've fixed/changed/improved: Several scanline issues: fixed The sometimes weird movement of the infection objects: fixed/avoided The "can't shoot" issue in the Intracellular screen when the ribosome is up by the cell membrane (there was a controls conflict with the "bump" action... should be much better now. I'm motivated to get this right after I noticed during the most recent ZPH show that controls got the most votes for the most important game attribute!): refined Screen/mode flipping back and forth between the 'Intracellular' screen and 'Exocellular' screen at more frequent but appropriate times: refined Missing sound effects for some events: fixed/added Limits on collecting some of the "power-up" objects: added Background colors a bit darker in a few cases so play objects contrast against them better: refined Changes to the initial state values and screen-to-screen re-initialization to work better in the dual-mode back-and-forth play sequence: begun refinements Health score bonus after clearing a tissue in the Exocellular screen was not added correctly: fixed and much, much more! To-do before the next playable demo: Implement difficulty setting* in the gameplay of the Intracellular play mode and adjust it a bit in the Exocellular mode as well Complete the most critical changes to the initial game state values and screen-to-screen re-initialization Fix kernel visual glitch on Intracellular free virus (color of first sprite row(s?) not correct) when at top near cell membrane One more sound effect? I don't think the to-do list will take very long. With luck tomorrow I can get the next demo ready and released! (I have a work holiday for my day-job ) Longer term, I'm thinking about: Continued refinements of state initializations, limits, scoring, etc. to have a well-balanced game in terms of challenge/reward/fun Summary screens as intermissions between the play screens, showing your incremental change of state (e.g. how many antibodies you gained, and how many new viruses escaped) Two player mode(s?) with couch-compatible game selection (Earlier in this thread I brainstormed several varieties of two-player modes... some of those may be too ambitious for the size of cart I want to make and my available dev time...I don't want this game to take forever!.. So for now, any two-player mode is likely to be fairly straightforward. However, perhaps later, after some other Atari dev projects I'd like to do , I could revisit this and make a deluxe-expanded "Super Immunity" release with additional gameplay options! ) Better (i.e. more comprehendible?) display of current vitamin and energy levels (number of power-ups you've collected and not expended yet) * For difficulty in Intracellular mode, I'm thinking about the following for Beginner ('easy') setting compared to Advanced ('hard'): Number of infecting vRNA strands per screen is fewer (e.g. 8 vs. 12) After implanting, each vRNA strand will produce fewer new virus copies before expiring (e.g. 4 vs. 6) Energy level cannot drop below 1 (meaning you can always "kill" infection object in beginner mode... but doing so can cost in the overall Health score depending on vitamin level) Bouncing an Energy Molecule with the Free Ribosome will always direct it downward rather than down, sideways, or upwards Energy molecule random initial position will generally lower on screen (closer to mitochondria) Speed of all objects generally slower, time between random motion changes generally longer (already true in Exocellular mode) If you played the current demo releases yourself, or watched my Odysee videos or the ZPH play-throughs, and you have any feedback in general or reaction to this comment, please let me know! I may not be able to implement everyone's suggestions (especially if they conflict), but I'm sure there's some great suggestions out there!

Good thread, @splendidnut. I had not noticed that one before or when I posted (I should have looked around a bit harder before I posted ). I hope I don't need to devolve that far in terms of debugging! I think manipulating the .sym file based on symbol capitalization would work pretty well for me and not be too hard to implement... my build script could invoke the .sym file filter to re-order the symbols so upper-case symbols are moved to end of the file. Hopefully Stella won't choke if I do that!