Okay, I think I've figured this out. Evade the cats, collect the birds, and if those kittens get a little too close... wham, throw something heavy at them! And KILL them.
Get more birds into the exit at once for bigger combo bonuses. Watch out though, as every time you kill a cat, another one appears out of the cat boxes on the level.
Bonus time! Catch the little birdies fired up by the cats before they splat! I guess I know what the cats keep all these birds for now. They never attack them, only you. When you die, all the birds are released back onto the level. So the cats can use them later for birdlaunching.
The levels spin around and wrap, so enemies you escape on the right will soon be coming up on your left.
Wait, is that bird wearing sunglasses? It's probably a smart idea in this place. I can barely even see the birds or items against the backgrounds.
Two cats? Now you're just being ridiculous.
Okay, that background is just a step too far. I CAN'T TAKE ANYMORE!