Got it as part of the latest Humble Indie Bundle, started it after my first Skyrim playthrough. Crazy hard and crazy fun. I doubt I'll go for the Achievements, since a good chunk of them are "clear [world] without dying" but I will be, at the very least, going for A+ on every stage.
This game is also the second-biggest cause of hand cramps in my life.
The biggest cause is handwriting, you sicko