The story centers on an elderly widower named Carl Fredricksen and an earnest young Wilderness Explorer named Russell who fly to South America in a house suspended by helium balloons. The PlayStation 3, Wii and Xbox 360 versions of the game follow the film's plot more tightly, spanning eleven levels, with some liberties taken. The Microsoft Windows, Mac OS X. PlayStation 2 and PlayStation Portable versions are a much looser adaptation, in which Carl and Russell take longer detours through the jungle to attempt to reach the end of Paradise Falls. Consequently, those versions are over 20 levels long.