It's true.. it's kinda hard to innovate (both with story and gameplay) with FPS' now-a-days.. but there are some nice elements to this game.
Your "nanosuit" has multiple basic elements to it, armor, strength, speed, and stealth. You can easily switch between all, and should, depending on what you're trying to accomplish. Each, naturally, with it's own +/-. But it's not, 'I do this whole level on stealth".. I frequently switch between 2 or 3 of them in a 30 second period.
Plus, this lends itself to different styles of gameplay. I don't care for stealth games. I prefer front assaults. One can do both with this game, though it's far harder to kill enemies (freaking body armor!), so cover and stealth are important. Plus there are loads and loads and loads of enemies to kill.
The AI isn't particularly all that smart, but enemies will take cover and try to flank you and work in groups to do so. But they don't seem to run very hard when I drop grenades on them. Maybe because I have it on easy. It's still pretty challenging.
The weapon mods are.. meh. Nothing special there. Mostly just looks cool.