I cracked a few games, looked at someone else's code but I can assure you that at the ASM level, it's very hard to understand that phong-shading routine to the point you can actually re-code it yourself...
Depends on the game. Some games had so few comments that they looked pretty much like a disassembly (Pac-Man for the Atari 800 had exactly two comments in it -- one was a copyright statement, the other was "Ha!", on the critical write-to-ROM for its rather pathetic implementation of copy protection).
I cracked a few games, looked at someone else's code but I can assure you that at the ASM level, it's very hard to understand that phong-shading routine to the point you can actually re-code it yourself...
(yes, I've tried :-))
stF