I think you left an incredible first impression with the first song of the soundtrack, it screams "promotional trailer" with the high energy it gives off.
The abundance of ambient songs fit since you are basically making a fps game where the music isn't the full focus of the game and mainly brings the atmosphere. The frequent use of samples throughout your soundtrack is also great and really fits into the theme.
Now when listening to the boss themes, maybe because I haven't played any of your inspirations you mentioned; it kinda fits for a boss in Terraria lmao. Anyways, you did spectacular with the soundtrack and I hope you do more of this.
Still, 20 tracks is absurd, it's incredibly longer than I expected but I fully enjoyed that journey