I would imagine either the worlds are huge or there are several levels per world. I would have a hard time justifying a $40 purchase on only 3 worlds otherwise. I'm pretty excited about this game, but money is an issue and Amazon just charged me for Code of Princess last night. Epic Mickey, which I've yet to buy, dropped in price pretty quickly so hopefully, Power of Illusion will as well. This one is 2D and uses sprites. I can't not buy it.