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
00:07 1-10 Muda Madness (Dragonzamasu boss fight)
10:24 1-F3 Dire Dire Docks (Secret exit, Dive Man boss fight)
23:34 1-F3 Dire Dire Docks (Normal exit, Wendy boss fight)
31:30 1-11 Rift Valley
37:21 1-12 Spiral Tower (Normal exit, Mouser 2 boss fight)