If I remember well, the 65c02 adds new instructions compared to the
original 6502. If some false opcodes (not used in the 6502) exist in
the 65C02, they will be interpreted and therefore the program will not
behave correctly. That is what I have seen with Gamma Goblins, I have
been obliged to replace the false opcodes with NOPs so that the game
now works correctly on my IIgs.
I would say that the cracker of Lady Tut could have replaced the false
opcodes to make the program understandable. Let's ask JPL ;-)
I cannot recall the name of a game that did not run on a specific
machine due to one VBL softswitch ($C019 or $C070), hardware
differences may explain the issue not only the opcodes.
I believe it is better playing on an unenhanced IIe ;-)