I finished it a few days ago and man, I loved it! It would have made my list for games of the decade if I had played it sooner, I'm sorry Arkane I failed you!
It's one of the very best immersive sims I've played, with tons of little secrets and hidden details that make you feel clever for figuring them out. The overall story kept me on my toes for most of the game, there's interesting reveals and twists and turns throughout. The character stories you encounter are also well crafted, I genuinely wanted to help or avenge some of them after getting to know them, if only via recorded messages and emails.
One amazing detail is that every single member of the crew has a name and job, and they can ALL be tracked down. Security terminals have a full list of the crew and their locations, which you can browse and investigate regularly. There are no random dead bodies here, every single one has a story.
It's definitely not meant to be played as a shooter, you'll get wrecked, except near the end when you've acquired enough combat skills. But if you enjoy sneaking around and picking off enemies one by one, carefully exploring every single room you visit, reading notes and emails to figure out secret safe codes, and so on, you'll be in heaven.
It's gorgeous too, Talos 1 is one of the most striking and believable videogame environments I've ever visited, and it feels great when by the end you barely need to use the map anymore because you know the place by heart.
I can't recommend it enough if you're into this genre.