Hurry-Scurry Galaxy

Hurry-Scurry Galaxy is a galaxy in Super Mario Galaxy. Whenever Mario or Luigi step on a tile, it'll disappear within a few seconds. There is a planetoid with the shrinking tiles and a black hole in the center. Therefore, Mario of Luigi can't afford to stay in one place too long.

Trivia
In the misson, "Hurry, He's Hungry" in the Sea Slide Galaxy, most of the level's layout is similar to this galaxy.