Wavespark is a chilled out one button physics game. The idea is simple: There’s a ball, moving along a wave, and your one button is used to increase gravity. Therefore, when the ball’s going down a wave, you can give it a boost by increasing gravity, flinging it up peaks. You have to keep going as long as you can. There’s nothing else to it!
Your score increases the longer you last, as a timer counts down, so if you go to slow you won’t reach the next checkpoint. There are four game modes, Distance, Bonus, Time Attack (my favorite) and Free Play. Requires Flash, and plays in your browser.