From Wikipedia: Mario is Missing! is a geography-based game for the PC, Macintosh, Super NES and NES. It was developed by The Software Toolworks and released in 1992 for PC and SNES. In 1993, the NES version was made and developed by Radical Entertainment. All three versions were published by the Mindscape. Mario is Missing! is the first Mario game to feature only Luigi as a playable character, which did not occur again until Luigi's Mansion.