Escape Goat is an excellent little puzzle platformer with a sort of NES sensibility and well-crafted levels. About the only bad thing I can say about it is that it's too short -- if you're a skilled platformer, you can get through it in under two hours -- but that is, in its own way, praise.
You play a purple goat who, according to what passes for a story, is attempting to escape from prison, which evidently involves getting through a set of platform levels. The challenge of the game is less in the platforming itself than in puzzle-solving; the controls are crisp and responsive, there's no combat as such, and the main challenges navigational.
Your goat can jump and double-jump, and can also "dash," which among other things can destroy some types of terrain through butting, and can also move some others (think blocks of ice). In addition, he has a mouse companion, whom you cannot control directly, but can release; the mouse crawls in a predictable pattern, and can get through narrow spaces that you, Mr. Goat, cannot. Sometimes you find a "magic hat" in a level, which the mouse wears; this allows you to swap locations with the mouse, also essential for solving some levels.
There's quite a lot of variety in the challenges the levels pose, and in the nature of the terrain and obstacles you encounter. Each level involves getting to a door (and, often, collecting one or more keys to unlock it first); and quite often, switches reconfigure the level layout. This means there's often a bit of trial and error in figuring out what switches do and how to trigger them to get what you need; and it is possible to get yourself into a position from which you cannot recover. But you can always "suicide" and restart the level; since they are generally fairly short, this is no great frustration.
Escape Goat has already had some success as an Xbox indie; it's recently released for PC (and is available for the next few days as part of the Indie Royale bundle. Thereafter, it will be available from the developer's website. Unless you have some objection to retro graphics and gamestyles, I suspect you'll enjoy it.