M-4 to 2600 port - just goofin'

[Atari-Jess]

If this gets made, you should use a text style label so that it appears like a 1st gen Atari title.

 

I know it's boring but it would be so much more authentic.

843583[/snapback]

 

It looks like we agree with each other!

[vdub_bobby]

If this gets made, you should use a text style label so that it appears like a 1st gen Atari title.

 

I know it's boring but it would be so much more authentic.

843583[/snapback]

 

It looks like we agree with each other!

902468[/snapback]

That is a good idea...but this is going to end up on a multi-cart, I hope.

[vdub_bobby]

Well, I said final...but here's another, more final version.

 

Changes:

Modified (improved?) enemy AI.

Modified sound effects.

Fixed bug.

Optimized some routines; got it down to just a hair over 3K.

 

Also, would someone be so kind as to test it on real hardware?

 

Thanks.

m4.bin

[Cybergoth]

Hi there!

 

I can't figure out why the game apparently allows for scores into the thousands - I don't know how you could possibly score that high in 90 seconds.  The best I've been able to do (through MAME, never played it in the arcade) is in the low one-hundreds.  Maybe there's something I'm missing?  Anybody know?

 

Well, I'm the 9th best M-4 player in the world, with a score of 136

 

Current World record is 329.

 

Ok, just ran it on the real thing, looking good to me. Very close to the original!

 

Greetings,

Manuel

[vdub_bobby]

Well, I'm the 9th best M-4 player in the world, with a score of 136

 

Current World record is 329.

 

Ok, just ran it on the real thing, looking good to me. Very close to the original!

 

Greetings,

Manuel

903272[/snapback]

Thanks, Manuel. Good to know it works fine on the real thing.

 

Anybody have comments about the sound effects and enemy AI, especially?

 

Got it under 3K right now. Just 2K worth of fat left to trim

 

[retrocon]

I enjoyed playing this. I just vaguely recall maybe playing this once in the arcade. Don't think it was out there very much was it?

 

Anyway, I think I found a sure-fire way to kill the opposing tank every time. I just go up to the top and shoot the top three pieces of his shield. Then I wait with my tank about one down from the top. Inevitable he moves up to the very top and stops. He's just a fish trapped in a barrel there and I can usually kill him in one or two tries unless he's very lucky.

[vdub_bobby]

I enjoyed playing this.

Good! And thanks!

Anyway, I think I found a sure-fire way to kill the opposing tank every time. I just go up to the top and shoot the top three pieces of his shield. Then I wait with my tank about one down from the top. Inevitable he moves up to the very top and stops. He's just a fish trapped in a barrel there and I can usually kill him in one or two tries unless he's very lucky.

What's the highest score you've gotten doing this? Just out of curiosity.

 

And, yeah, the AI is pretty simplistic right now. Basically, every 1/2 second or something the tank checks to see if it is moving towards you; if it isn't, it changes direction. And every ~1/8 of a second it checks to see if a missile is moving towards it and, if so, changes direction to move away. And it fires constantly.

 

Once I'm done reducing the ROM size as much as possible I'll probably go back and rework the AI a bit in the larger version. Anybody have any brilliant ideas for a good AI algorithm?

[retrocon]

Hmm, never noticed the score before. Just tried it and got 195, is that good? I think I could do 300 with a little practice. I just go for the tank. I don't go for shields or cars. Don't know what the best strategy is though.

 

This is fun though. I think I love these simple games the best, so pure.

[vdub_bobby]

New version - possibly the last version

 

Changes:

Most notably: the tanks move at half their former speed. This matches up better with the arcade original.

Second-most notably: big modification to AI.

Added color mode back in, is now the default. Switch between color and B&W with, counterintuitively, the COLOR/B-W switch

Slight tweaks to graphics; mostly the explosion graphics.

Slight tweaks to sound.

 

I'm open to suggestions for the colors of the color mode. I'm also open to any other comments/suggestions/complaints. Fire away!

m4.bin

[vdub_bobby]

New version; small change:

 

added console-type detection (2600 vs. 7800) and will read the B-W/Color switch differently than the Pause button on the 7800.

 

I would appreciate it if someone with a 7800 would test this out for me.

 

Also, anyone have any comments about the enemy AI? Too easy? Too hard?

m4.bin

[retrocon]

Also, anyone have any comments about the enemy AI?  Too easy?  Too hard?

 

Limited testing, but I like it much better. There's more movement and its tougher to pin him down.

[vdub_bobby]

Slight changes to timing of some things, fixed a sound glitch, and maybe other things I don't recall.

 

Still 3K. Any ideas for the other KB of ROM?

m4.bin

Edited August 16, 2005 by vdub_bobby

[vdub_bobby]

Added PAL mode - select with the right difficulty switch (A = PAL, B = NTSC).

 

Also fixed a scanline bug when both tanks were hit at the same time.

 

Still 3K and I'm still not exactly sure what to do with the extra 1K. Also, batari, I think I moved everything off the bank-switching hotspots.

m4.bin

Edited August 22, 2005 by vdub_bobby

[mos6507]

I think it's time to think up some variations ala Combat.

 

For instance, you could make the barrier scroll in one variation.

 

You could also try steerable missiles or varying missile and tank speeds.

 

I actually think it's better to reserve the difficulty switches as a speed handicap and just compile separate NTSC vs. PAL binaries.

 

Last time I checked I also didn't see any screensaver mode.

[retrocon]

You could also try steerable missiles or varying missile and tank speeds.

 

916496[/snapback]

 

Yeah, I was thinking along those same lines. How about powerups when you hit those fast moving vehicles in the background?

 

Things like:

 

player-guided missile

multi-missiles

shield renewal

speed up tank

 

These might be a fun way to mix it up. Also, in more advanced levels, maybe the computer could actually have some of these better weapons as a handicap to the player.

Edited August 23, 2005 by retrocon

[mos6507]

How about having a row of blocks in each corner to indicate cities or a something? Then you would have the tension that comes from deciding whether to attack or defend.

Edited August 23, 2005 by mos6507

[+Nathan Strum]

I like it. The AI is pretty good. You have to pay attention to not get killed (which isn't always the case in many 2600 games).

 

The scoring is a little... interesting. For instance, I managed to destroy the enemy more times in a game, yet still lose. Since he shoots pretty much constantly, he racks up more points by knocking down your wall, than you can just by conserving your shots and just hitting him.

 

I'm not sure if that's good or bad, since it forces you to be a little more reckless than you would otherwise, just to build up your points.

 

Another game option (if you're looking for 'em) could be to reconstruct your wall. Perhaps by holding fire and moving the joystick towards the enemy. (Although this just gives him more opportunities to score... so maybe that wouldn't work so well.)

[vdub_bobby]

I like it. The AI is pretty good. You have to pay attention to not get killed (which isn't always the case in many 2600 games).

Glad the AI seems to keep things interesting.

The scoring is a little... interesting. For instance, I managed to destroy the enemy more times in a game, yet still lose. Since he shoots pretty much constantly, he racks up more points by knocking down your wall, than you can just by conserving your shots and just hitting him.

Happens to me pretty often as well - though, actually, if you are hitting him more often and still losing, it is probably not because he is shooting more wall than you (each section of wall is only 1 pt), but more likely because he is hitting more cars/airplanes than you. They are worth more points than the tank. Which is a little odd, I think, but its the way the arcade original works.

 

Adding options (steerable missiles, scrolling walls, etc.) is a good idea.

[vdub_bobby]

Looking for ideas.

 

Here are the game-play variations I've come up with so far:

 

1. Steerable missiles

2. Scrolling walls

3. No walls

4. Rebuilding walls (i.e., every X frames, a wall section is randomly rebuilt)

5. Invisible tanks

6. Unlimited ammo

7. Shorter game (30 sec vs. standard 90 sec)

 

2 & 3 are mostly mutually exclusive; other than that all combinations of the above could be played.

 

So...any thoughts? Think any of these variations should be ditched? Have any others that you think should be added?

[Zach]

Hi Bob, I finally got around to trying M4. Nice job. I like all the ideas for variations too. The more, the better, in my opinion.

 

BTW, you are going to allow the reset switch to work in the middle of a game, right?

[vdub_bobby]

BTW, you are going to allow the reset switch to work in the middle of a game, right?

Yeah, I suppose.

[+Nathan Strum]

How about richoceting walls? You could only shoot through gaps, and if you missed, your shot would come back at you.

[retrocon]

More ideas:

 

bombs - you shoot them over, but they don't explode right away. You have a few seconds to wait for the enemy tank to near and then press the button again to detonate.

 

first aid - tanks take two hits to kill, but after first hit, a random first aid icon appears and if the tank makes it over to it before getting hit that second hit is restored again.

 

panic mode - you have x number of seconds, lets say 20 seconds to hit the other tank or you die. A hit just slows the tank down, doesn't kill it but it does reset your 20 second clock. Player who loses is the first player not to hit the opponent in a 20 second span.

 

sniper - you each only have one shot at a time and after you shoot you have to wait for your opponent to shoot off his shot before you can reload (or other way around). Like a shootout at the OK Corral.

 

warp - you can space warp ala asteroids once each life.

 

tunnel - going to the top or bottom will take you to the other side.

 

pong version - you actually can't let a shot get by you. The first player that lets one get past them loses.

 

multi-player tank - one player shots, one player moves tank - player VS player mode of course too (it probably has that already, haven't checked).

 

three tank version - 2600 could probably handle this well. Have three tanks vertically adjacent to each other. The tanks move up and down as one tank. Press button to fire middle tank, button + up fires top tank, button + down fires bottom tank. Good luck keeping all your tanks in one piece.

 

sandtrap - there are random patches (sand traps) in your path that are sticky and your tanks passes through them slowly. In these places your tank is particularly vulnerable.

 

 

That's it, my brain is spent.

[vdub_bobby]

More ideas:

 

[...]

 

panic mode - you have x number of seconds, lets say 20 seconds to hit the other tank or you die. A hit just slows the tank down, doesn't kill it but it does reset your 20 second clock. Player who loses is the first player not to hit the opponent in a 20 second span.

This is interesting...not sure how much play this would add, though.

sniper - you each only have one shot at a time and after you shoot you have to wait for your opponent to shoot off his shot before you can reload (or other way around). Like a shootout at the OK Corral.

I like this; I had thought of something similar, actually: your tank only can hold one bullet at a time. This is an interesting variation, that you have to wait for your opponent to shoot as well.

warp - you can space warp ala asteroids once each life.

 

tunnel - going to the top or bottom will take you to the other side.

These are both interesting, and doable, though I don't know if they fit the theme very well. And they would require major modifications of the AI routine, which I'm reluctant to do at this point.

pong version - you actually can't let a shot get by you. The first player that lets one get past them loses.

Maybe a little too counterintuitive.

multi-player tank - one player shots, one player moves tank - player VS player mode of course too (it probably has that already, haven't checked).

player vs player is already in, and the gameplay is so simple (can only move up or down and only shoot in one direction) that I think splitting up the duties would make for a very boring experience.

bombs - you shoot them over, but they don't explode right away. You have a few seconds to wait for the enemy tank to near and then press the button again to detonate.

 

first aid - tanks take two hits to kill, but after first hit, a random first aid icon appears and if the tank makes it over to it before getting hit that second hit is restored

 

[...]

 

three tank version - 2600 could probably handle this well. Have three tanks vertically adjacent to each other. The tanks move up and down as one tank. Press button to fire middle tank, button + up fires top tank, button + down fires bottom tank. Good luck keeping all your tanks in one piece.

 

sandtrap - there are random patches (sand traps) in your path that are sticky and your tanks passes through them slowly. In these places your tank is particularly vulnerable.

These would require major rewrites to the kernel and/or code so I'm a bit reluctant to tackle these. The sandtrap idea and the first aid idea, though cool, are essentially impossible, since they would require a complete rewrite of the kernel. Well, unless the sandtraps were invisible. But that would be lame.

 

Thanks for the ideas!

 

How about richoceting walls? You could only shoot through gaps, and if you missed, your shot would come back at you.

Might be cool. But it would require maybe more coding and additional RAM than I am able to devote to this at this point. Though the more I think about it the more I like it. Maybe rather than bouncing shots, have indestructable walls. Hmmm...

 

And thanks to you too.

[Cootster]

Really fun game, another awesome piece of work from you . . . Nothing like the feeling you get when you see that plane or car go boom when you manage to shoot it. And it looks great in B/W, which is strangely rare for 2600 games. Even Atari's official titles never really optimized for it.

 

One thing that might make the AI act more like a human would . . . Is it possible to have it count the shots the player has left and save its remaining shots for when the player is loading? That's one of the best strategies: Unload the first 10 shots continously along with it, reload, and concentrate on keeping it away from cars/planes until it blows its load, then start blasting away at it. Not only would the AI not be a sitting duck so much of the time, it wouldn't get so many cheap hits in on the cars/planes (which it doesn't even try to aim at, correct?).