Well on Snowmans Land (Level Ten), theres that wind right? As Mario Luigi or Wario, that'll blow off your hat. You'll find it on a snowman. Kill the snowman, and get your hat back. Now, lose your hat again. This time, when you kill the snowman, there'll be two. Repeat again and there'll be four. Then eight. Then 16. Then 32. Your game should start to slow down. Do it once more and the game crashes.