Super Mario Galaxy/Freezeflame Galaxy

Freezeflame Galaxy is accessible from the Bedroom observation dome. You need 26 Stars to enter.

Star 1: The Frozen Peak of Baron Brrr
Boss fight.

Star 4 (Cosmic Comet): Frosty Cosmic Mario Race
Available when a Prankster Comet is in this Galaxy. Race a mirror of yourself to reach the Star.