The backgrounds can get a bit much. Luckily for everybody, you can change them in the Options menu. You can turn them off completely or use a more subtle setting like this:
Thanks for playing!
Viewing post in Marty Mouse's Missing Millions comments
I'm still kind of bad at it but I'm getting better, I've now managed to unlock level 3 :)
I noticed when you bubble a cat they can still kill you for a moment.
You could add a time bonus to each round to add a bit more replayability for good players, of course it should be less than a cheese bonus to keep that as priority for scoring.
Btw if you were to make it a paid game at Steam, cat games do well, please add online leaderboards :D