Recently I discovered that people have actually started working on Mushroom Kingdom Fusion again, after it was in hiatus for a long time. It used to be maybe my favourite fangame ever, combining all kinds of different franchises while still keeping the Super Mario Bros 3 / Super Mario World style gameplay.
The game still isn't finished but I'm surprised they're working on it at all.
Levels included in this video:
00:00 Intro
00:22 -1-5 Doh's Dimension
15:02 -1-6 Red Rock City
23:29 -1-7 Battle for Dirt Hill
29:49 -1-8 Neon Labyrinth
39:11 THE END