Super Mario Dark World - Part 2 - Speed Test is one of those weird, unofficial Mario hacks that flips everything you know upside down. It’s still classic SNES platforming, but the levels are darker, tougher, and full of little surprises—like enemies in places they shouldn’t be or jumps that feel just slightly off. The "Speed Test" part isn’t kidding either; you’ll either nail the timing or faceplant into pits a lot.

First time I played, I got wrecked by a random Piranha Plant hiding in a pipe that normally wouldn’t have one. The physics feel a bit heavier than vanilla Mario, so you’ve gotta adjust. Not for the faint of heart, but if you’re into ROM hacks that actually challenge you, this one’s a solid pick.