I like the psychological vibe of the OST! The piano in the first track would sound better with looser quantization to lean more into the intimacy of the soundscape. I like the chord shifts you made in the 2nd track (some sus chord resolutions). A little bit too simplistic, so maybe include light accompaniments from a synthesizer to add more variety. I really like the change in vibe with the 4th track! The layering of bass, with synth pads, synthesizers, and vocal choir, is a really unique soundscape, amplified further as you start to distort it with an electric synth over it. That one is my favorite track, in terms of how well you developed the melodic idea and layered it. The intimate organ playing in the 5th track is pretty nice. Nice variety overall! I think if you had more unique sections in some of these tracks to add more moving parts, it would prevent it from sounding a bit monotonous with the ambiance, but just a suggestion. I like the soundscape you have going on.