This is a good one. Very short, very sweet, very simple. Definitely not as investing as Cave Story but that's a high bar anyways, plus it's a lot easier which I think serves as some good compensation. I didn't actually buy this (as it was gifted to me by XenonNV) but I can confidently say it is worth a purchase.

Oddly enough, holds a rare title of the ice level being my favorite. Is that fucked up or what?