NO SPOILERS.
The director that should be given credit is the director of photography/cinematography, Pawel Pogorzelski, the story line and sub plot climaxed at strange points and was wondering around with nothing to grip into.
The visual representation of flipping feelings and psychedelic hallucinations surpassed the strange gory story, and really gives you a real taste of a trippy experience, for the good or bad.
Half way through the movie I didn't know whether to leave or stay for the subliminal story told through visuals, but for some reason I couldn't look away.
I do know one thing, if you've never had a bad trip on mushrooms this movie will help you understand, and you'll leave the theater feeling gross.