Buggy
I have never used flash to make things before so I don't actually know specifically how to fix this but it seems like your aren't grouping events together correctly. Like the fact that there are two ball counters (so if you "run out of ammo" before you actually run out, that's why), sometimes blocks get moved but not deleted and you can bug it out to have infinite balls by shooting blocks while your combo is still going on.
I thought it was a lot of fun but at some point I couldn't get past the level because it kept saying I was out of ammo early.