X, a prototype game for the Nintendo Game Boy, was released only in the USA. As a prototype, information about its full gameplay or production is likely scarce. The prototype status indicates that it's an unfinished or pre-release version of the game, meaning it might have unfinished features or significant differences from a full retail release. Without more details, precise information on the title is unavailable.

X (USA) (Proto)

WWF Superstars 2 (USA, Europe)