The first two phases are basic (Aside of Pizzaface's true form as pizzahead) but after beating Pizzahead, you are lead to a fakeout victory, just for him to heal himself, summon the previous bosses and taunt you over it, Peppino at this point is absolutely D O N E with Pizzahead's antics, so he gives the game's most impressive scream and beats the shit out of the bosses, the rest of the battle is less you fighting the bosses and more they fighting you, ,not even Pizzahead is safe, since he literally doesn't take the battle seriously, all you need to do is wait until he opens himself and finish him once and for all