This was probably a good premise for a movie. If it was, the entire thing was ruined by carless, inconsistent, lazy writing.
I know this will be a criticism lobbed at literally every single movie from now on, but this felt like it was written by A.I.
The monsters were 4 different horror movies monster tropes just depending on what particular scene it was.
They are vicious mindless mauling animals in one scene
They are extremely slow moving, smart, calculating, sadistic, shape shifting, intelligent infiltrators in one scene
They are a weird pack of aliens that form into a big rolling teeth wheel that chases people down just like in the b movie "critters" from the 80s.
Spoilers
The boys spend 15 years visiting the neighbors farm, but then the neighbors are going to have a bunch of fun shooting the boys feet off at the drop of a hat?
These creatures, that are whatever the plot wants them to be at any given moment, spend 15 years trying to scratch through a house door, while ignoring the enormous glass windows? And then out nowhere they suddenly get smart and break into every single house all at once, except by tunneling in and again ignoring the giant glass windows even though they've been trying to beat down the doors 2 ft away for the last 15 years?
I could rant forever. This movie feels like A.I. took a bunch of tropes, mashed together a script that made zero sense and then a bunch of people who didn't care made it into a movie.