Playing Wii or a Wii game so much that you go into almost a relapse state from being away from it. Usually caused by playing the game on a friends console, or one that you don't have accessible. Symptoms include raving on about the game you were playing and trying to convince people to get it. Or trying to convince your parents or yourself to spend the money and buy it.
After playing Paper Mario for three hours straight at Belle's house, Annika fell into a Wiilapse when she got home. That is, until she invited Belle over again to bring her console.