All boss battles (including final boss, true final boss and secret bosses) of Super Mario Miracle 2 on hard difficulty and without taking damage. You can tell how often I had to retry by how quickly I skip past the dialogue.
Super Mario Miracle 2 is a Collectathon-style episode for the SMBX engine inspired by games like Super Mario Odyssey. You can download it here: www.smbxgame.com/forums/viewtopic.php?t=29787
Timestamps:
0:00 Boss 1 - Laki
1:11 Hidden Boss A - Mother Computer
1:52 Boss 2 - General Bob-Omb
4:00 Boss 3 - Sky Piranha
5:44 Hidden Boss B - Red Vortex
6:25 Boss 4 - Funky Boo
7:56 Hidden Boss C - Blue Vortex
9:40 Boss 5 - Black Mass
11:14 Boss 6 - Lady Manic
12:45 Boss 7 - Incognita
15:21 ...