I'm not sure. I was able to destroy the blocks in Stage 1 just fine, but some of the blocks wouldn't get destroyed in Stage 2. I'm not sure if that's a bug, or if there was something I had to do to increase my attack or something?
My chain never got stuck or anything like that.
The actual gameplay mechanic is really fun and seems to work well. Flinging the ball around was pretty satisfying.
EDIT: Actually I realized, am I supposed to destroy the enemies, not the blocks? I figured I had to avoid the enemies.