The only thing that DX:IW impoves its predecessor on is the graphics.  The gameplay and story are both vastly inferior to the original Deus Ex.
Story - Probably the best thing about the original, Invisible War's story is by contrast extremely weak.  The way the story transitioned from the original is probably the most suspect link in the story.  The ending of the original gave the player three distinct choices to make, and as you go through the story in Invisible War, it seems like Eidos tried to meld all three options together (otherwise there would be no story I suppose).  The story also throws in some very out of place references to various modern day conspiracy theories just to make the story "cool".  Perhaps Dan Brown wrote the story for Invisible War.
Gameplay - The most bizarre part of the game is how Eidos decided to "dumb down" the gameplay from its predecessor.  Instead of a system of experience points in tandem with biomods, the only character development system in the game is the biomod system, which is very similar to the biomod system of the previous game.  Also strange is the "universal ammo clip" system.  Apparently, in the future, stun prods use the same ammo as rocket launchers and flame throwers.  They even dumbed down the lockpick/multitools system.  Now there's only multitools, which gained the ability to pick the locks on doors.
Despite its inferiority to the original, Invisible War is still a somewhat enjoyable game.  It's just a bit dissappointing because the original was *that* good.
The only thing that DX:IW impoves its predecessor on is the graphics. The gameplay and story are both vastly inferior to the original Deus Ex. Story - Probably the best thing about the original, Invisible War's story is by contrast extremely weak. The way the story transitioned from the original is probably the most suspect link in the story. The ending of the original gave the player three distinct choices to make, and as you go through the story in Invisible War, it seems like Eidos tried to meld all three options together (otherwise there would be no story I suppose). The story also throws in some very out of place references to various modern day conspiracy theories just to make the story "cool". Perhaps Dan Brown wrote the story for Invisible War. Gameplay - The most bizarre part of the game is how Eidos decided to "dumb down" the gameplay from its predecessor. Instead of a system of experience points in tandem with biomods, the only character development system in the game is the biomod system, which is very similar to the biomod system of the previous game. Also strange is the "universal ammo clip" system. Apparently, in the future, stun prods use the same ammo as rocket launchers and flame throwers. They even dumbed down the lockpick/multitools system. Now there's only multitools, which gained the ability to pick the locks on doors. Despite its inferiority to the original, Invisible War is still a somewhat enjoyable game. It's just a bit dissappointing because the original was *that* good.