Grimm: A Disgusting Platformer Adventure
Grimm is a strange game which mostly involves you playing as a small, bearded man and making the landscape rife with dirt and destruction, which oozes from your person as you walk. It's pretty fun. I particularly enjoyed turning cats into cat skeletons with my mere presence (they seem just as happy as skeletons).
The game has a fairy tale/fable basis to its plot, and comes in episodes. I've only played the first episode so far (which is free, yet somehow still drops trading cards on Steam), but it's been lots of fun. It plays a lot like some of my favourite old PS1 platformers, and one of the main mechanics is "buttstomping" - where you stomp things with your butt (did I need to explain that?).