Atari 8-Bit Crystal Castles 6-1-84 Update

[Tempest]

As some of you may know the 6-1-84 version of Crystal Castles was thought to end at stage 2-2 as the game just failed to advance to the next level at that point.  However thanks to @Scooter83 we've now discovered that the game will actually advance if you let it sit long enough.  Usually this only takes a few minutes but sometimes it can take much longer.  The prototype actually has all the levels in it, but this bug pops up randomly as you play.  Sometimes the screensaver may even kick in, but if you wait long enough it will advance to the next level (thankfully you're invincible in this version).  I've found that sometimes moving around helps, but I'm not sure what causes the bug or what helps get past it (other than waiting).  Perhaps @Kr0tki can look at the code and see?  The bug always happens at the end of 2-2 but then happens randomly after that.

 

My best guess is that the code that checks how many gems are left and the code that governs Bentley and the Gem Eaters picking up a gem has a bug in it.  Maybe picking the gems up too fast or at the same time as a Gem Eater throws the count off and the game still thinks that there's a gem left and therefore won't advance?  Why waiting fixes this I don't know but there may be some sort of error check if the game sits on a level too long that catches the issue.  I'm also not sure why this always seems to happen on stage 2-2 but then randomly after that.

 

http://www.atariprotos.com/8bit/software/crystalcastles/6184.htm

 

Crystal Castles 6-1-84.bin

[Kr0tki]

The issue is, level 2-2 contains invisible gems on the elevators. They are briefly visible when the maze is being painted:

Then, while the sprites drop from the top, some elevators are randomly redrawn with a graphics glitch, which causes a gem to disappear:

Then, once gameplay starts and the elevators start moving, all these gems disappear:

But the gems are still there. You can hear the audio cue when walking on an elevator indicating that you have picked a gem up. When all gems, including the invisible ones, are collected, either by the player or by the enemies, the game will advance to the next level.

[Tempest]

5 hours ago, Kr0tki said:

The issue is, level 2-2 contains invisible gems on the elevators. They are briefly visible when the maze is being painted:

Then, while the sprites drop from the top, some elevators are randomly redrawn with a graphics glitch, which causes a gem to disappear:

Then, once gameplay starts and the elevators start moving, all these gems disappear:

But the gems are still there. You can hear the audio cue when walking on an elevator indicating that you have picked a gem up. When all gems, including the invisible ones, are collected, either by the player or by the enemies, the game will advance to the next level.

Ah ok.  So I imagine this happens on other stages with elevators too?  Is it on all stages with elevators or only certain ones?

 

I assume that the gems on the elevators aren't supposed to be there and they're put there accidentally?

[Kr0tki]

Elevators on stages before 2-2 don't contain gems. I haven't bothered to check the later stages. Since the gems were removed from elevators in the later prototype, I would assume they were placed there by accident.