The Ludum Dare game jam series has been going on for a while now, with its 28th iteration coming up next month. Ludum Dare 26's theme was "minimalism," and one of the titles to come out of that event was Leaf Me Alone, a 2D exploration-based platformer starring a little tree person (or something).
Set against serene music and chirping birds, Leaf Me Alone puts the player in the environment with only the basic controls of moving and jumping explained. Within a few minutes, I was on top of a tree where I found a leaf that could be used as a sort of parachute, Wind Waker style. Though it started as a small game jam title, Leaf Me Alone was added to since the competition, and is now an adventure that takes a couple hours to complete.
If you're bored at work and can hide a browser game from your superiors, then you might want to take a look. Leaf Me Alone can be found on AddictingGames.com.