Even if you use the Game Genie invincibility code, the Sega Genesis version of Chakan is STILL a hard game to finish, and that's saying something. I don't think that there's a lot of people that have actually completed the Genesis version without cheating, although I know it can be done (just not by me
). I've beaten the Game Gear version without cheating, but that's shorter and easier to begin with.
Incidentally, the Game Gear Chakan death scream is completely different than the Genesis one. And, for reasons I cannot fathom (extra memory and nothing to do with it?), the title screen actually says "Chakan: The Forever Man" in digitized speech.