18
The last level of Mario Wonder is way too hard
(hexbear.net)
Tabletop, DnD, board games, and minecraft. Also Animal Crossing.
Rules
This is the level you unlock by 100%ing the game (all seeds, 10-coins, and flagpole tops)
I'm glad they keep the option out there for true Mario sickos, but I've skipped that bit in most of the recent games lol