The game features numerous differences from the previous Pac-Man World games, placing an emphasis on action and combat whilst still preserving most of the platforming elements. The Butt-Bounce move is now modified so that it can only be done three times at once, with the third bounce creating a small shockwave that slightly extends the radius of the attack. The Rev-Roll is mostly the same, but can now be stopped before launching Pac-Man by pressing the jump button. (wikipedia.org)