Walker is a free one-button game about John's commute to work every morning*, from the four poster bed in which he enjoys his point and click dreams to the sturdy oaken desk at which he delivers words to the eyes of the world. It's not as simple as something like Canabalt, where jumping and fleeing are the order of the day, instead presenting a complex and cleverly designed world to platform through. Some obstacles will make Walker turn and walk in the opposite direction (mostly ghosts, he hates ghosts) and all you can control is when and how high he jumps. Sadly not by shouting 'jump' at him, but by pressing 'z'. Free, fairly lengthy and quite charming, Walker is available here.
It must be said that while I enjoy the game, Walker's habit of sitting on cacti is extremely unattractive, particularly so given that they eventually kill him. He's got a good wall jump on him though and sometimes he attaches a boot to his head and that sort of lets him fly.
If you manage to see his adventure through to the end you're a better man than me. I gave up when a penguin accidentally punctured him with its beak as it slid across some ice.
* Walker is not actually about John at all as far as I know. It is, however, a delightful and smartly put together platform game. Do try it.