On Level 2: Snow Go, you aren't supposed to be able to get the red gem until far later into the game. You're actually supposed to fall from above the red gem from another bonus level accessed in a later warp room. However, with a well-timed spin, slide, jump, and slam, you can get it on your first playthrough of the level! IT takes me a few tries, obviously. It's always stuck with me as a cool glitch.
![](https://i.ytimg.com/vi/iEcjR5RkJ24/maxresdefault.jpg)