MNSSHP is as much for adults as a "daytime visit" would be.... you can still experience the best rides PLUS you have the fun of the decorations, Halloween parade, special fireworks, and LOTS of other things that you can only see/do at MNSSHP!
My Dh and I always start the evening with dinner at LTT before the party begins -- the CM's there are made up with "ghoulish" makeup and the characters are in their Halloween costumes.... by the way, the food is wonderful too!!