What room opens once you beat the snow level on super Mario 64?

Answer 1

Unless you have a certain number of stars, no room opens when you beat any level. It takes

8 stars to get into "Bowser in the Dark World"

8 stars to get into the "Cavern of the Metal Cap"

8 stars to get into "Vanish Cap under the Moat"

10 stars to get into "Tower of the Wing Cap"

10 stars to unlock the "Big Boo's Haunt" (unconfirmed)

30 stars to unlock "Dire, Dire Docks"

The star from Bowser's submarine to get into "Bowser in the Fire Sea"