Sonic the Hedgehog 4

Sonic the Hedgehog 4 was a hoax game produced for the Nintendo SNES at the same time that Sonic 6 was produced for the Game Boy. This time, the game is a hack of Speedy Gonzales - Los Gatos Banditos. The gameplay takes a poke at the Mario games: Mario has been captured, and it's up to Sonic to save him.

Various versions of the game have been spotted: a NTSC cartridge (which locks up after level 1), and a PAL cartridge (which locks up in the middle of level 4). A 'fixed' version allowing the player to beat the game is floating around the Internet.