Second half everyone turned into the dumbest people on the planet. I started rooting for the killer to kill all the stupid people (which was everyone). I mean dead bodies will stink and you can't just leave cars running with dead people in them. You will get noticed that way. The reviews are all over the place but RT is at 77%. Not sure how or why.
shareI'm not expert, but doing some quick searches it seems it can take a few days before the body starts stinking to where people outside of the room would notice.
https://affinitybioaz.com/smell-decomposing-body-dissipate/
If the room is air conditioned it seems plausible. It really only seemed like a few days from the killing of the guy Remy hid under the bed to the end. As for leaving a car running, I presume she would have turned off the car engine of that guy she killed in the pit. There was blood splatter on the glass. Maybe she came back and cleaned it up a bit later.
I did like the first half better as well. Though I will say a character I felt certain would die ends up the only one standing when the movie ends, and a character I thought would most likely make it didn't. So there's that.