Now that Deus Ex has been cancelled, what other games scratch the Deus Ex itch?

Well, it is from 2010. But I will still recommend Alpha Protocol.

AP is one of the greatest RPGs of all time with amazing mechanics, your choices really matter and the dialogues are amazing. But at the same time the mechanics are janky AF, some skills are bonkers and the graphics are mediocre even for the era.

A must play in my book!
- I thought it reviewed badly? Or is it one of those games that bombs on release and then it grows on people?
While it scratches the immersive sims itch...it's not a good game by any means
- It certainly has its problems, but I had a lot of fun with it back in 2012 or so.
Can't buy it anymore. Only through piracy.

EYE Divine Cybermancy if you are into weird shit .

You gain brouzouf
That game kind of haunts me to this day. I tried it first when I was too young to understand game mechanics or English. Then, after several years, I tried it again. Got farther, but got stuck on some cryptic shit. Tried it after several more years and I was even more confused how many mechanics the game has.
- I tried it first when I was too young to understand game mechanics or English.
  
  Knowing English doesn’t help much in EYE tbh.

I think you might like Deus Ex. You play as this dude named JC Denton and you try to solve who stole the Statue of Liberty's head. I think. It's been a couple years. But I rememer the voice acting being top notch, especially in the Hong Kong level

Nothing scratches that Deus Ex itch like Deus Ex.

Vampire The Masquerade: Bloodlines

PC stuff, multiple choices, conspiracies, all there.

Definitely this. It was one of my most favorite games at the time I played Deus Ex HR, and it's exactly the game it reminded me of.

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.

Man, System Shock 2 was so good
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.
- You should check out System Shock 2, Prey, Dishonored, Ctrl Alt Ego, EYE: Divine Cybermancy, and other Immersive Sims, or "Box Stackers."
System Shock doesn't really share anything with Deus Ex except that it's also cyberpunk.
- 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.

Cyberp-

pre-2010

Ah shit.

I'm kinda struggling to think of any that are pre-2010 and not Deus Ex. Dishonored kinda?

Dishonored is 2012. I've got absolutely nothing.

Honestly I think Prey fits the request closer than Dishonored but that was released in 2017 so it's waaaay outta scope.
- Damn, now I feel old haha
  
  Still haven't played Prey but I keep hearing it's amazing.

It's not quite as deep down the solving missions without bullets rabbit hole, but STALKER: Shadow of Chernobyl is ripe with disturbing mystery and conspiracy. It gets darker and weirder with each abandoned secret lab that you explore, and as you get closer to the center of the Exclusion Zone. I wish I could replay it again for the first time.

Absolutely loved STALKER. Heart of Chornobyl comes out this year.

I'm curious why you're only interested in pre-2010 games to replace a hypothetical future Deus Ex release.

I love the jankiness of the era. I also played most of the post-2010 games that are similar to it.
- Interesting. Well, I hope you find what you're looking for!

Only one I can think of is AC1 and AC2 to a lesser extent.

Not pre 2010 but Shadows of Doubt is worth a mention. You are a former cop turned private eye, solving crimes in a procedually generated city trying to make ends meet. You pick locks, hack emails, use air vents and "Jensen your way in" to chase leads, collect evidence and bring justice that the megacorporation government won't.

It's far from perfect but is the best "Deus Ex 1 we have at home" I've seen.

Transistor. Not pre-2010 but 2014 and checks several boxes here.

Oh did it get better? I tried it back in the day and had a hard time getting into it.
- It was always a great game IMO, nothing fundamentally changed about it. But I also understand what you mean. I bounced off it once or twice because the combat system is very, very different and I wasn’t sure I was getting it. Didn’t quite find a flow.
  
  Eventually I just sat down and beat it, because it’s actually not a very long game. Like 5 to 7 hours. And the story/music/art is just unbelievable.
  
  You don’t need to get great at the combat. Just kind of learn what builds work for you and be a little flexible when they’re not working.

As one person mentioned, EYE Divine Cybermancy. Not sure if it's pre-2010, but it's good. Iirc it was originally intended to be a Warhammer 40k game, but the devs couldn't get the license. As such, Warhammer 40k fans in particular will probably enjoy it, even if all the Warhammer 40k specific stuff has been stripped out or reskinned.

A post-2010 game would be Cruelty Squad. Looks and sounds like shit, but the gameplay is fucking amazing and the crustiness makes sense in the context of the game's world. It's set in a "final-stage" capitalist/cryptobro hellscape where you work as a for-hire hitman. There are no good people left, morality is dead, and death is only temporary. Don't worry about collateral, everyone's evil in some way, so go gas a cruise ship to kill a mob boss and don't feel bad about it. Features an augmentation system which lets you use your appendix as a grappling hook or install an organ to generate ammo, so it's more biopunk than cyberpunk, but damn the game is fun. I know this is patient gamers, but it's worth the full price. Trust me, sire.

Eye was one of the first games I bought on steam and I don't think I've ever played more than 30 minutes of it. It just seemed so janky and didn't really guide you at all. Am I missing something? Because I really like the aesthetic and the customization seems awesome but it just seemed a little obtuse to me.
- Nope, it's just super jank and could really be improved with some kind of tutorial. It's fun if you manage to get past that though.

Ctrl Alt Ego is new, but is a fantastic immersive sim. If you want pre-2010 though, you're limited to System Shock 1 and 2, Thief Gold/2: The Metal Age, Hitman: Blood Money, and the original Deus Ex.

Immersive Sims are coming back, but pre-2010 cuts you to essentially the formative classics of the Immersive Sim genre.

If you want to branch out of the strict boundaries of Immersive Sims, Fallout: New Vegas and Vampire: The Masquerade - Bloodlines are both incredible.

Added Ctrl Alt Ego to my Steam Wishlist - never heard of it, great tip!
- Indies are absolutely crushing it, especially in the ImSim scene. Not an ImSim, but In Stars and Time recently blew me away with how much I loved the characters, even if it was cheesy.
  
  I'm a half-patient gamer, I play older AAA and AA games, and newer and older indies. It's a good mix!

The original version of Syndicate.

System Shock 2 for old school, Prey (2017) for a more recent one.

Doesn't check all the boxes, but Metal Gear Solid 3: Snake Eater hits a lot of notes, most notably in the boss fight department.

3rd person, Cold War spy, stealth, action game

A hunger mechanic that effected performance (stamina and at around 50% would affect aim or have stomach growls that would alert enemies) and could get food via hunting, trapping or stealing and in a few situations could be used offensively
Camo system
Majority of the bosses that you could defeat lethally or no lethally
Medical system was pretty nifty, not fully realistic doing first aid during battle, but had the spirit of battle injury management
Can get a lot of lore tidbits here and there by being stealthy and eavesdropping either being nearby or using a longe range listening device and by communicating with your operational support

And there is probably other systems I am forgetting ( played it on a ps2 many moons ago). Seems there is a pc version but appears to be a port and with a controller requirement, but otherwise I thought it was a loaded game for its time ( released 2004)

There's always the system shock remake that is pretty darn good if you're looking for something nostalgic but updated.

It's also 35% of at GoG right now.

Cyberpunk. Not to the same level but you can see the Deus Ex inspirations. The release debacle I side I think the current game version is more than adequate to fill the Deus Ex shaped hole anyone may have.

You should play / replay Splinter Cell. Espionage, stealth action, some techy tools. Really would like to see this series or something like it return.

There's also Metal Gear, Shadowrun, and the lesser known Anachronox produced by Tom Hall of Doom.