A supreme disappointment.
The game follows a ll new character, but unfortunately the developers did not manage to give him the same "coolness" factor JC had. The end result is that you play a dweeb that you don't really give a damn about. The story opens with you being attacked in your local Tarsus academy, which allows you to escape. You set off to figure out who's pulling the strings, a lot like Deus Ex 1.
Unfortunately, it's not very interesting. All of the organizations are so radical it's hard to find anyone you'll like. Extremes are taken to the point of being disgusting. Due to this the ending seems irrelevant, and implausible.
Another issue with the story is that you're choices seem meaningless. There are no consequences for anything. Murder is wanton and goes unpunished. You can betray a faction and they'll forgive you...again, and again, and again. While these decisions were probably made to cut down on frustration, it's too heavy handed. Choices have consequences and Invisible War fails to show that.
Gameplay has been changed a lot. Skills are out, and combat has been changed. Biomods are simplified. The scale of the game is noticeably reduced, and is disappointing. Removing skills is the dumbest choice on part of the developers. While I do have a heavy RPG slant in my blood, removing Skills added nothing to the experience and takes away a very important part of the Deus Ex experience. Progression.
As for combat, removing the skills has a big impact. Aiming is more accurate and shooting is definitely better. Still, it has a long ways to go. By removing stat-driven combat, Invisible War has to compete with the greatest shooters...and it can't. Aiming is clunky, and bullets weak. Weapons have no real power and aren't satisfying to use as a result.
Biomods are no longer a hard, strategic choice. They can be switched out at will, leaving no real purpose to even think about your decision. Canisters now add biomods and upgrade them. The fact that any canister contains any power undermines another aspect of the original's decision making. There are less slots too, again we can handle it, don't dumb it down.
The game inherited Deus Ex's poor AI, and managed to make it downright stupid. Enemies commonly don't react to being shot. They ignore the bodies of their fallen comrades. They give up searches almost immediately. If you find a good sniping spot, you can kill practically an army, no sweat. In the actual cities, people do absolutely nothing, ever. It all feels lifeless, The complete opposite of the original's cities.
The interface is horrible. Everything is too concerned with looking aesthetically pleasing, not being functional. There's no map system, the inventory is a pain, and all the HUD elements clutters up the center of your screen. There is a fade option, but a little thought on the developer's end would've been appreciated. It's a real struggle to get the smallest bit of info from the menus which is not a good thing.
Honestly while the graphics are better technically, Artistically and in terms of style Deus Ex 1 wins out. Character design in Invisible War is horrendous. Everyone is horribly ugly, unrealistic, and dweebish. The environments are too "new" and perfect. In the supposed "dusty" parts of town, chrome plating is everywhere. Worse, the environments have been scaled back, which makes them noticeably less impressive.
The last major gripe is the game's length. I beat this in little under 6 hours. SIX hours. Most shooters are about that long today, but back then at least 10-15 hours was the standard. The original was 20+ hours. If you do all the side quests expect about 8-10 hours tops, there's no real place to explore anyway.
Deus Ex Invisible War is a decent enough of a game. it still has more player choice than many games put together but when you compare it to it's predecessor, it can only live in shame. Everything is a step down from the original, and the story is so poor (in some cases it's borderline stupid) that there's no point in playing this if you have played the original.