After the outsider had beaten Giga Bowser in Melee, Sonic the Hedgehog, a distant traveler outside of the Nintendo Multiverse, teams up with Mario to defeat Bowser and Dr. Eggman from merging both their worlds together. But to get to them, they'll have to compete in an all-sports tournament, which includes kart-racing, olympic games, golf, tennis, party games, and a fight to the finish!
