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
00:21 7-S6 Neo Tokyo
07:49 8-1 Superflat World
11:24 8-2 The Bitlands
15:15 8-3 Pipe Labyrinth
20:05 Break the Targets
20:59 8-F1 Midoro Palace (Normal Exit, Helmethead boss fight)
50:27 8-F1 Midoro Palace (Short search for Secret Exit)