I liked Prey a lot! It took me 60 hours, though. I also started with human-only mods but eventually grabbed some alien ones. They were definitely quite fun and made for some interesting ways to solve puzzles.
Prey was one of my highlights in recent years. Liked it to the point I almost made 100% achievements AFTER I completed it twice - both pure human and "pure" alien playthrough. Then on my last run I had to kill personally every NPC in-game and the "big typhoon thingie" managed to ruin it for me and killed ONE person. Damn.
But really, I wish to see such a game of this quality in the immersive sim genre at least once every few years.