M.K. Rhodes’s review published on Letterboxd :
"George reached. The clown seized his arm. And George saw the clown’s face change[...]; what he saw destroyed his sanity in one clawing stroke. 'They float,' the thing in the drain crooned in a clotted, chuckling voice. It held George’s arm in its thick and wormy grip, it pulled George toward that terrible darkness where the water rushed and roared and bellowed as it bore its cargo of storm debris toward the sea. George craned his neck away from that final blackness and began to scream into the rain, to scream mindlessly into the white autumn sky[...] 'They float,' it growled, 'they float, Georgie, and when you’re down here with me, you’ll float, too–'[...] Everything down here floats,' that chuckling, rotten voice whispered, and suddenly there was a ripping noise and a flaring sheet of agony, and George Denbrough knew no more.[...] The left side of George’s slicker was now bright red. Blood flowed into the stormdrain from the tattered hole where his left arm had been. A knob of bone, horribly bright, peeked through the torn cloth. The boy’s eyes stared up into the white sky, and[...] they began to fill with rain.”
That's really good, isn't it? The brutality of the violence; the funereal remove of the narration—poor Georgie's mutilated body discarded like trash on the side of a suburban street. His arm was enough for IT, like a finned shark thrown back into the sea to drown and die; the horrid, senseless waste of it all.
And this movie, in turn, makes a complete and total waste of its source material. How dumb is this IT? It takes the "They float" mantra—an almost Lynchian bit of surrealist-horror wordplay—and literalizes it. Like... the kids actually fucking float down in the sewer. Pennywise just has a big ol' stash of kids floating around down there, and when he is defeated and they start to descend, one of the characters informs us via dialogue that the kids are falling back down, like it's not something we can plainly see for ourselves.
I've seen Goosebumps episodes that take their sources of alleged fear more seriously than this county fair funhouse hokum, which in terms of both tone and actual aesthetics (all those goofy canted angles) resembles, of all things, a Chris Columbus Harry Potter movie.
The performances from the child actors are impressive, and sure, it's "competently made" (whatever that means)—but so what? King's novel is not a masterpiece—like all of his work, it's too messy and indulgent and bloated for that—but what it does have is a dark, feral, seedy power that belies its more ludicrous and melodramatic aspects; it seethes with genuine menace. What it most certainly was not is an Amblin movie, and it definitely wasn't tepid trash like Stranger Things. This is a movie that treats the threat of a father molesting his daughter with the same level of seriousness as a shitty CGI creepypasta monster that crawls out of a dumb painting. It's King's novel fed through the same meat grinder that spits out a thousand Conjuring spinoffs, emerging as just another piece of artless, neutered, multiplex horror product.