I think I've figured out the cause of my "Stop going through my line you stupid ball!!!" problems. If I make a V to catch the ball quickly, it one side of the V is kinda close to vertical the ball says "I'm going up through a line so don't hit it." Since the ball's going up through a line ever is the STUPIDEST FEATURE EVER, if you just fixed that then the ball would stop going through my V traps.
Hmm... scoring really not consistant. Being buried under a wall sometimes doesn't score, and then you can never score. They are safely buried under tons of stone. And balls hitting other balls is weird. You can smash walls, but hitting another ball and you practically stick.
I know what is wrong with the scoring. If the first two levels each had a 1000 quota, and I score 2000 on level 1, I shouldn't be able to fail level 2. Make the quotas game-long instead of level-long. Then it wouldn't feel so crappy when you blitz a tower and then choke on the next one.
Nearly awesome. More wall types would be cool. Some sort of feedback on where you released the ball too. Even just a background would help. Plus, if you kill the king or do a slow full-tower topple on the last ball, it doesn't score any points. Wait to score until I hit space one last time or something. And maybe instead of throwing back to title screen, do a "Retry level with 50% points?" option like some shooters do.