Tip about his final form, his wave shit cant actually hit you if you stand next to the brick in the corner it collides with the brick and never hits you (I stood at the bottom right brick). Also he cant actually stomp you when he is huge, it seems like you should stay away, but just walk up to him and keep hitting him with your meat, he will actually flinch and back off a bit every time so you never get stomped.
I'm still woefully bad at Balloon Fight and still stuck there ._.