I came across a game crashing glitch. It happens if you don't have the "RISE!" achievement yet, and are trying to get the "I.C.B.P." achievement. Basically, if you fly over The Wall, the cutscene will play out as it normally would, but then, there is a small chance your penquin sandbag might be commanded to rise and fly some more. After that, it will freeze on the screen of the penguin staring into the distance.
 "UPGRADE COMPLETE!"){kind=icon}
 "Epic Battle Fantasy 4"){kind=icon}
 "Learn to Fly 2"){kind=icon}