Hey Indy... yeah, in the readme for the emulator, I mention the 3 games that don't work right...
Stampeed - the cattle flicker in weird ways. Happens on Windows version of BLISS as well. Unknown cause.
Nova Blast - game will freeze several seconds into playing. Does not happen on Windows version of BLISS. Likely cause is that the game does something "unusual" and we've removed most of the normal emulator safe-guards to get maximum speed.
Q-Bert - game will lose a life after completing every screen/board. Happens on the Windows version of BLISS and also happens on the MAME/MESS emulator for the same game.
I haven't spent any time on causes yet... two of the 3 issues have been in the BLISS codebase (which is what I started with) for decades. To be honest, none of these is a great loss... Stampeed offers nothing to the 3 other versions (Atari 2600, 5200/8-bit) that you can already play with my other emulators. Q-Bert isn't anywhere near the best version of that game - B*nQ on the 7800 runs fine on A7800DS and there is an NES version as well - both of which are vastly superior.
Nova Blast is probably the only game I'd like to run correctly. It's not a great game, by any stretch... and it's better on the Colecovision... someday I'll figure out what that program did differently and try to add support for it.
Emulation is rarely perfect
You can bet that if it was classics like the AD&D games or Beauty and the Beast that wasn't running right, there would be no end to the hours of my day tracking those bugs down!