Play Primarily as Phineas because he is the most powerful. Avoid the punches by running to each corner narrowly avoiding them. When the lasers appear, avoid those two. Then spam primary fire. On the last possible second, press X to push two more hits. Rinse Repeat. Make sure you can beat him before the fifth wave, because the punches last twice as long and the lasers lag the game out then, causing time loss.

:)