Played this to judge it, really fun.
Noticed two bugs: select does weird things to the colors, and on the second level I fell through the broom 6 times, only on the 7th try it managed to pick it up.
Oops! Select turns on cpu debugging, I forgot to take that code out.
Oops again! The broom collision is buggy because it is biased to the left. In level 2 I decided to be fancy and have the player approach it from the right. Luckily this fix is easy, I can move the broom's collision box to the right a bit.
Collecting the broom has nothing to do with how many flies have been killed, just what part of it you're touching. Sorry for the confusion!