I love the storytelling within Mainshock! Any kind of music where segments reflect an actual moment in the story always make my brain do a happy dance, haha. I won't repeat your description of the track, but it's executed so perfectly and I can see it all play out as I listen to the music.
Overall, the OST is delightfully atmospheric, giving a wonderful sense of isolation and dread. Mainshock & Surface Tension are my 2 favourites, but the whole thing is one of my favourite submissions that I've listened to so far! I wish I knew how to make stuff like this, haha. I am but a humble noob, but I can dream x3