I played the game and reached level 24, then died( Wonder what the ending is all about.
It has it's vibe and i enjoyed the core loop, but after level 10 the game gets repetitive and after level 17-ish it lags like crazy. Presumably because of these birds that have not unloaded after the attack. Difficulty felt fine, but only because i was able to abuse the strat of luring all of the flying cheese guys into the fire, and it feels kind of random, whether this move succeedes or not.
Edit: now that i checked, those were indeed squirrels, and not flying cheese balls. What a shame.
Overall, nice little game that needs some balance tweaking.