Break up some objects on the back of the Leviathan and assemble the pieces into a generator. Use Thor to charge up the generator, but this also causes more chariots to appear. Charge up Thor and use his lightning attack to shoot them down.
After shooting down the chariots, assemble some pieces to the right of the generator. Using Hulk, pull on the handles and pick up a fin. Move to the right and push the buttons that appear on-screen to finish off the Leviathan.
