Prelude: Big extended piano chords paired with a lush reverb. 5/4 time signature is very digestible due long pauses and where the notes are are positioned in the piece. Mysterious, nice introduction to hook the player.
First Self: Different song but it feels like an extension of the Prelude as it has some similar structures. Borrowed chords add some nice harmonic interest.
35:79: I thought it was going to be quite a slow and contemplative soundtrack and suddenly a battle theme explodes. Punchy breakbeat combined the piano stabs create an interesting polyrhythm. Lots of dissonant chords make the battle stressful.
Timespace: Follows the chord directions of the Alchemist theme in a different key. Harmony starts to get really otherworldly (I-II-VI at 0:24?), it really feels like you're traveling through the infinite. Woodwind was really surprising at the second part of the track nice touch.
66:66 PM: Chiptune arpeggios against a breakbeat. It feels fuller with more instruments and more musically developed. It doesn't feel as stressful as 35:79 due to it being more dissonant, it feels like there is a threat but the player has more control this time.
Faced with the Other Self: Faster version of the alchemist theme with some punch from the staccato string chords. Feels very imposing.
There was a nice contrast between the tracks full of physical instruments and the ones which used synthesizers and drums as it's main instruments. Excellent production skills, all the instruments were high quality and the mixing was great. The compositions were harmonically complex and engaging. There are some good melodies, though it sometimes felt like the melodies took a bit of a back seat. Nothing wrong with that though, soundtracks can be good without an in-your-face melody all the time, and it seems that this was the style you chose to go for this jam. Overall a high quality soundtrack, good job.