Firstly, the script is not that great. Some scenes feel like a waste of time. These just drag for no reason, not really establishing anything. Yet new characters appear out of nowhere and still get no introduction anyway. The editing also doesn't help, it's messy and constantly trying to be artsy. There's too much pointless symbolism in this, it's just a basic case of "trying to look smarter that you are". The whole "slowly going insane" thing was managed poorly and the film feels like a disjointed mess rather than a journey down into insanity. The ending love drama while being somewhat justified still doesn't work because they wasted too much time on pointless things and "smart symbolism" instead of building it up. I can see such a story work, but it's just not done well.
Secondly, the main lead's acting hurts me. He's not a good actor and he is constantly bad in this. His acting never changes to reflect any changes in his character. This also takes away from the story. The girl was an ok actress and this film just feels like a waste of her talent. This is a competent film, they had a nice location, some CGI here and there, and this looks good since it was shot on Red cameras (as mentioned in the credits). Some of the music tracks were good, but most of them were misused to build up tension out from nowhere.
What it all boils down to is that this could've been a good psychological love drama. The way they did it is just a boring mess nobody is going to sit through (besides me of course). I wish they would rethink and re-write this and try again, this might work.