Batman: Return of the Joker Trivia (NES)
Cancelled SNES portAn SNES port was nearly completed but ultimately not released, though the ROM is available. Interestingly, it seems to have been made separately from the Genesis version and uses different art assets.
SoundsThe short tune played during the "stage clear" screens was first used for the same purpose in the Genesis version of Batman: The Video Game.
Information also contributed by chirinea.