Super Mario Fusion was a console game featuring Mario in a crossover in the world of Sonic the Hedgehog, another video game character.
Bowser has joined forces with Dr. Eggman and they have a plan to get rid of their enemies by sending Eggman's robots into both of their worlds. Rosalina and Peach tell Mario to gather all the Stars before Bowser does. In Sonic's world, Tails and Knuckles tell Sonic to close down the trap doors. Unfortnately in Mario's world, the robots are dressed up as Sonic and in Sonic's world they are dressed up as Mario starting a classic Fight. Afterwords, they realize that they have been tricked by their enemies whick starts a new Friendship. Not even Bowser Jr., Rouge the Bat, and E-123 Omega can stop them. But Bowser gets in with the big guns and gets the Dark Star to kidnap Peach and Knuckles. Sonic frees them while Mario distracts the Dark Star on Yoshi. Peach has an idea: if Mario and Sonic can put Tracers on Bowser and Eggman they can find their secret Base. Mario fights Eggman but forgets to put the tracer on him but Sonic does and they are able to find their lair. After they have defeated Bowser and Eggman, they say their good-byes and return to their home World.
- Metal Dark Sonic
- Bowser Jr.'s Takeover Machine
- The Dark Star
- Egg Hedgehog Bot