The high ratings you see are people who were obviously involved with the project and are a bunch of liars. The script seems like it was written by a fifth grader with no life experience trying to sound profound.
Plot? What plot? All sensibility of a plot went out the window with the stupid pseudo-narrative words that came up on the screen before the first shot ever took place. Some survivors are companions and so are some ghosts, but some aren't? However, if you are a ghost then you can only move so far from where you died. Unless you are a survivor, and then you can move about just like everyone else who is alive can. So who is the companion? A ghost that tries to kill you but can't move far? Or a live person who can? Do companions in real life try to kill companions? Not that I have ever seen. The entire movie is more confusing than a Rubik's Cube.
Acting? What acting? I've seen better acting by kindergartners performing a ten-minute play in the school lunchroom.
Cinematography and Direction? Don't ask. This is, by far, one of the worst pieces of junk I have ever laid eyes on. Give "Companion" a big pass. If you happen across it anyway, you'll wish you had listened to me. This is straight-up garbage!