Fan sequel
Super Mario Fusion
by Judgespear · Platformer
Crossover Mario fan game, later Mushroom Kingdom Fusion.
Judgespear's Mario crossover fan game, later Mushroom Kingdom Fusion; the original site is gone (fan continuations such as Super Mario Fusion: Revival are on itch.io at https://fusion-fangaming.itch.io/super-mario-fusion-revival).
Built upon Super Mario (1985).