If you're looking for a more atmospheric experience, Dreams' Halloween event, All Hallows' Dreams, may be for you. The whole thing is user-generated, like the rest of Dreams, and All Hallows' Dreams pops up at the top of the world list when you boot the game up.
Choosing it takes you to a dream world with different scary mansions to explore.
Some are reportedly very scary indeed, though they have their biggest frights confined to the upper floors. Others are just fun, creepy haunted houses to explore, complete with pumpkins carved by other Dreams players and a costume zone.