Originally Posted by bippym
It would be possible, but not easy.
It's not usually just a case of replacing a few raw gfx files, you'll have to know exactly how the gfx are stored and ensure your gfx follow exactly the same layout/methods etc.
Also there are palette considerations not too mention the fact the game might need to be dis-assembled, modified and recompiled!
Worth the hassle? dunno you tell me!
then this possible with some mushrooms
and a huge of crazy works