Really really love this! The found footage style and general gameplay/ambiance reminds me a LOT of Slender.
In fact, it could be kinda neat to introduce some more Slender-like mechanics and an objective beyond just avoiding Fen. Maybe the player could try to collect pages/car parts/other scattered items, but with each item collected, Fen grows faster and more aggressive? Just a thought :)
Also, would it be possible to make the hypnosis stronger? I find the hypno mechanic REALLY hot, but it doesn't feel like it's strong enough to actually make escaping Fen that much harder. An option to make the hypnosis faster and more effective (slowing player speed and more strongly locking the camera, and maybe even causing the player to move towards Fen when hypno has been active long enough) could be very fun.
This is super impressive work, and I'm excited to see what comes next :)