Algodoo

It's like circular pong, but it's special and you play it by yourself.
You control the white paddle, and the gray bumpers spin by themselves.
If the ball touches the red area, it gets killed, and you lose.
Give it a try!
Beware, ball gets faster the more it goes. If it goes fast enough to phase through the field, just consider yourself a winner.

Controls: Use [W] and [S] to move the paddle.