Even if you judge it as a pure action game, it isn't impressive. Here's how it goes:
1) Walk into a room. 2) Terrorists pop out of closets. 3) Take cover. 4) Aim at enemy's head (while you are still behind cover) when he predictably and consistently pops it out. 5) Fire. 6) Rinse and repeat.
Maybe it's just me but I'm pretty tired of heavily scripted, completely linear pseudorealistic military shooters. Now, if it's a heavily scripted, completely linear sci-fi arcadey shooter, that's not so bad because the enemy variety and actual combat tend to be much more engaging. Oh well. Hopefully Deus Ex 3 won't be as bad as DX2.