nsue/multiplayer-breakout — pull request #56 by koonwah (2014-09-03 02:28:43+00:00)
Title: Power up extra life

- powerup sprite is generated randomly (1 out of 40 chance) when the ball hits a brick
- when player's paddle collides with the powerup, he/she gains an extra life
- no more than 1 powerup can exist at the same time

Issue: https://github.com/nsue/multiplayer-breakout/issues/53