It Chapter 2 takes itself too seriously (as the nearly 3-hour running time would indicate), except when it doesn’t. Scenes of brutal violence set a dark tone and then it turns into a combination of Goonies and an amusement park haunted house ride.
It blatantly rips off Carpenter’s The Thing and then acknowledges it with a line from Bill Hader (redeeming itself, to my eyes).
Hader, in fact, seems to relax into the goofy spirit of the movie, even kind of making fun of it, and I ultimately had a good time when I did the same. No, it’s not scary, but how many movies really are (to adults, anyway). But it’s fun.