Ever wonder what Super Mario World could've been before Nintendo polished it up? This prototype—sometimes called the "Lost Levels" version—is a weird, rough-around-the-edges peek into early development. Some jumps feel just slightly off, a few levels have bizarre enemy placements, and there are odd graphical quirks you won’t see in the final game.

It’s not exactly harder, just… different. Like playing a familiar song on an out-of-tune piano. If you’ve memorized every pixel of the original, stumbling through these unfinished versions of Ghost Houses or finding missing sound effects is a neat little trip through Mario history. Just don’t expect it to replace the real thing.