Mario 4: A Space Odyssey is a hack of Mario 3: Around the World also developed by BMB and published by KDS. While this game adds a few changes, it plays pretty much the same as Mario 3: Around the World did.

Mario 4: A Space Odyssey's plot has Mario and Luigi watching the stars until a star crashes onto the ground. An Alien creature (despite the intro depicting multiple Shroobs from Mario and Luigi: Partners in Time, the text only states one) warns Mario and Luigi about an oncoming threat and that they need to stop the conqueror of galaxies with their army. (However, in-game there is no army that fight alongside Mario and Luigi).