Shell's Space!

Bancala Journal, BancalaWalker pg 252-255, translated

In the first mission of Slipsand Galaxy in Super Mario Galaxy 2, Mario or Luigi must slide down an extremely long slope. After they begin sliding, cylindrical Thwomp-like enemies called Rhomps appear from behind and attempt to squash them by rolling over them.

If the player is playing as Luigi and performs an extremely precise long jump just as Luigi is about to be rolled over by a Rhomp, Luigi will gain immense speed that will catapult him into the air as seen in the footage.

Unfortunately, there is no way for the player to slow down Luigi at that point, so that after flying far enough to exit the regular gameplay area, Luigi will leave the boundaries of the galaxy, and die.