This galaxy is unlocked by feeding the Hungry Luma outside the Gate dome 1,200 Star Bits. The Hungry Luma will only appear when you’ve completed Luigi and the Haunted Mansion and Gateway’s Purple Coins.
The goal of this level is to win the race against the Spooky Speedster.
As Boo Mario you can press A/B to fly higher and you can press Y or shake the Right Joy-con to disappear and float through walls.
There are no damaging enemies in this level. But you will find a couple of Banekitis in the second half of the race. They will not hurt you but if you bump into their springs, you’ll be slowed down and it might cost you the race!