Prey was an excellent game that I really enjoyed. To me it's not quite the same, since it's not as dense with people/NPCs. The only games that I can recall really coming close to Deus Ex are... Deus Ex Human Revolution and Mankind Divided.

Was it? You're not the first I've seen say something like this, but in both setting and mechanics I found it much more akin to System Shock 2.

I don't know, I don't see the similarity. I didn't really like Prey (or any prop hunt games for that matter). It's a new genre mix. I guess I can see the appeal.