So fun! Each track has a very distinct alien sound and it feels like each has it's own form of alien, feeling like as we are getting closer to the end we just end up finding weirder and more alien feeling things, which just felt great! I really love how you managed to pair those weird sounds so perfectly with some rock/metal elements so well! Your soundtrack reminded me a lot of Risk of Rain and the Golden Idol games!
Overall I really like all of them, but "Prepare to Engage" and "The Mothership" stood out to me the most, maybe because they both give off the feeling of retaliation, and feel like they are a continuation between themselves!
Great Job!