For free on Kongregate
If you're like me, you're a sucker for anything that attempts to recreate the nostalgic feeling of the Game Boy era. Tiny Dangerous Dungeons is one such game, and it has an open world to go alongside of its platforming conventions, resulting in a rather nice afternoon distraction.
The controls are fairly straight-forward -- WASD moves, jumps, and enters doors, and X/K throws knives. It's not a classic by any means, but it captures the old school feel of the Game Boy era fairly well, and of course -- it's free, which is always a plus.