How do you expect to keep your audience interested when there's no substance, style or involvement in order to prevent them from being bored? The Forest clocks in at a relatively short 93 minutes but even at that length it's rather tedious to sit through and never goes anywhere memorable.
Natalie Dormer and Taylor Kinney are decent enough in their roles, though I feel the dual role for Dormer could've been further explored and more prominent in the story, as it would've given Dormer the chance to boast her dramatic chops. Taylor Kinney is charming enough and performs admirably when a certain twist rears its head but these two stars deserve more meat on the role.
The dialogue is rather unnatural, you watch the film and hear lines delivered in the most unlikely of situations. There is a moment that backs this example in which Dormer's character Sarah bumps into a bloodied up school girl who looks frozen in horror. Sarah says "hi", in the most casual manner as if to completely ignore this girl is clearly in terror, and further weird interactions continue throughout the film.
The biggest issue of this latest horror film is the lack of atmosphere. When a horror film lacks an eerie atmosphere the scares and tone fall flat, and The Forest is a stale and very unscary psychological horror. The forest itself never feels menacing or unnerving, and the jump scares don't even try to make the audience shudder. Whilst that may not have been the intention, the resulting reaction is just the realisation of how cheap the shocks and tactics really are.
I was actually looking forward to this film a lot, the idea of a horror film set in the Aokigahara suicide forest should scream pure terror. However, the wasted potential is shocking. There are hints of bigger ideas that should've been explored even further, a prime idea is the use of tents for people who aren't sure about taking their lives. This film barely scratches the surfaces of what could've been a really solid horror film.