Physics game: UFO abduct animals

game play link here:
Drunk Pilot UFO

(initial sketch)

In the light of the UFO, the physics effect of water buoyancy is used, while the rest of the world follows gravity physics. This game features a UFO piloted by a drunk pilot, and players must control the randomly wobbling UFO to abduct randomly falling animals (with amusing sound effects). One bug I haven't resolved yet is that when the UFO touches an animal, the animal's alpha is set to 0 instead of being removed, causing invisible animal corpses to accumulate at the bottom of the screen. You'll notice this bug if you play for a while, haha.

(dead animal pile up)