I didn't like this, unfortunately (spoilers)
Even though it was uneven, I enjoyed the first film ... but 'It Chapter Two' was horribly written by Gary Dauberman, who also wrote 'Annabelle', 'Annabelle: Creation', 'The Nun', and 'Annabelle Comes Home'. Dauberman was one of several writers who contributed to the script of 'It', but he's the sole writer on the sequel ... and it shows.
'It Chapter Two' has too much comedy (like Eddie cracking jokes as he's stabbed in the mouth by Henry Bowers) and no genuine scares (unless you find people running from goofy CGI creations scary). There is a ton of blunt and expository dialogue, as well as cumbersome flashbacks to the first film, lumped in with even more flashbacks to events we never got to see that occurred during the timeframe of the first 'It' (something to do with the dodgy memories of the Loser's Club). They even throw in an animated flashback, like the opening of 'Black Panther', showing how It arrived on a meteorite and how Native American magic (?) can defeat it.
Not only that, but the music is obtrusive and self-consciously "epic" compared to the first film. And 'It Chapter Two' is a looooong film.
The main highlight was the cast. Unlike, say, 'Shazam', you get the sense that the adult actors were playing the same characters as their younger counterparts.
I also enjoyed the brand new subplot about Ritchie Tozier's sexuality (including his encounter with Paul Bunyan) - not only did it fit it nicely with the homophobic attack on Adrian Mellon, but improves on King's novel, which was pretty rife with stereotypes and gay panic. Although, it is odd that Ritchie gets so much attention in the second film (unlike Mike Hanlon, who is once again just a plot device). While Bill Hader was fine (he and James Ransone do the best with that lousy script), I am flabbergasted by critics saying that he deserves an Oscar nomination for this film.
Overall, I get the sense that the script for the first 'It' had time to gestate long enough in pre-development that someone was able to make a decent film from it. The sequel, on the other hand, was pumped out to a tight schedule by Gary Dauberman (which seems to be his sole strength as a screenwriter) and really suffered for that fact.
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