Movie about a group of strangers- around 5-6 people wake up in a field (maize/corn field?). They have no memory of why theyre there. At first we only see one or two people then they meet others (until theres a group of 5-6-ish people). All of them for some reason have a strange item they wake up with- I can remember someone I think has a knife, another a flask, and two other items might have been a map and a gun. These items turn out to be a piece of the puzzles they solve along the way.
Ultimately the movie follows the group trying to solve the puzzles laid out for them- and try to solve what is going on, and what monster is trying to kill them. One by one they all die or get lost. The final survivor is a woman (blonde?). I remember one of the characters is a black lady, another is an asian lady, a young skinny White guy.
At some point near the start of the movie they doubt whether they can trust each other. I think in the end of the movie one of the characters- I think a really strong war vet White guy ends up going crazy and becoming one of the monsters that were attacking them in the movie? I could be confusing that memory with another movie though.
The movie is in English. I watched this I think some time last year or the year before. It probably came out after 2014 but Im thinking it was even more recent than that probably after 2017.