This was fantastic! Dark and ominous, at times outright unnerving. Everything works together to build a really intense and oppressive atmosphere, from the superb sound design, the deliberate placement of music, the wonderful lighting and the gradual changes in environment from the mundane to the eerie to the horror.
Speaking of the gradual changes - this led to a fantastic escalation in tension. The opening set the tone, leading to the slowly narrowing tunnel which went on for long enough to evoke a real sense of dread. Won't list everything that happens as I don't want to give away spoilers, but some of the reveals really got me!
Was appreciative of the dialogue, as it provided a little light relief during gameplay but delivered in a way that felt natural and in keeping with the overall tone.
I wasn't able to figure out what I was supposed to find in the room of lights so didn't make it through to the end, but thoroughly enjoyed my time with the game all the same.