Knytt Stories also has an additional expansion pack with more levels available, and encourages users to actually create their own. Nifflas' signature style is truly unique, minimalist and both soothing and stimulating at the same time. He designs all of his own ambient music and sound for the games -- which means that fantastic scrabble-scratch-scritch-patter that Knytts and Juris make when they run, jump and scale walls is back for another go in the latest Knytt game.
It's free and the fastest easiest download ever -- it's just a single executable that doesn't get its hooks into your hard drive, so if you've never tried a Nifflas game, you have absolutely no rational excuse not to check out Knytt Stories.