Now that Deus Ex has been cancelled, what other games scratch the Deus Ex itch?
It's kind of sad that one of the greatest video game series is on hold for now.
Conspiracy theories, multiple ways of solving a mission, game lore hidden in computer inboxes...
Are there any (pre-2010) games that gave you the same feeling or do a similar thing?
There are some story-rich RPG shooters that are almost pre-2010 I could recommend, like maybe Dishonored or Fallout 3/New Vegas. But pre-2010 is tough, only ones I can think of are the System Shock or maybe Thief games.
I say yes both to SS2 and Thief 1&2. SS2 has several way for approaching most problems, a great story, lots of lore and a lot of character customization. It does lack story choice, but I feel thats ok for the setting.
Thief 1&2 are a bit more of a stretch, but if you like playing Deus Ex as a stealthy character, it will scratch that side of things. There isn't any character customization or story choices, but each level can be approached lots of different ways and they are all very atmospheric, with conspiracies and great story telling.
Thief is the only one that comes to mind from that era that holds a candle to Deus Ex's open-ended level design. Lots of different approaches to take on many of the stages. Well, as long as you didn't play on high difficulties, anyway.
There still aren't many games that go quite that hard on it. Open world games have a tendency to keep their set pieces much more simple. Maybe we'll see more of it now that Baldur's Gate 3 has made a big splash with the concept.
Dishonored is about as linear as Thief, open-ended level design, generally. Prey is closer to System Shock 2 in that it isn't quite level based but not quite open world.
If you mean linear in terms of level design, they are both pretty open overall, similar to Deus Ex. If you're referring to the actual Systemic game design providing new unique emergent solutions, then they actually beat Deus Ex in many ways.
The original 2 System Shock games are Immersive Sims. They have systemic game design as the core focus of how the player interacts with the challenges presented.