Your weapon runs out of ammo or speed or whatever you want to call it, and then you just get overrun. I like the combination of shooting and dodging the projectiles at the same time though. The sound is very obnoxious too, but I still liked the game.
This game misses the one biggest thing that makes a breakout game playable. When the ball bounces off the paddle, it should bounce as if it's hitting a curved surface. Right now, you just move the paddle to block the ball and wait for it to hit the blocks by chance. You can't actually control the ball, so there's no real skill or strategy involved.