Not really FPS, not really stealth game, not really RPG, but a mix of all three.
The game is the only one I know which does Die Hard 1-2 style very well. Combat is too deadly to go into a fair fight, so you spend lots of time in air vents, sewers, hiding behind tables and trying to be sneaky. But ultimately hell brakes loose, and then it's time to separate the enemies, pick them off one by one, make those revolver shots count. (at least, until mid game. By that time you can build yourself an FPS hero)
GOOD
* very well written NPCs. Outstanding job!
* voice acting is great
* support for lethal, non-lethal, stealth play
* looks good (except for that gold tint everywhere)
* level design is brilliant (multiple approaches, different kinds of roadblocks, etc.)
* initial setup is unique (security manager of a mid-sized company, not merc or gun-toting gangster)
* some of your choices matter in the game
* great style, art
BAD
* the hacking minigame is used much too frequently (you can skip the big majority of it, but _not_ all)
* the boss fights seem tacked on/out of place
* music is unimaginative
* restart test patience (first person intro cinematic+ mandatory tutorial area+ walk in the offices. Minimum 30 minutes before the game begins)
UNDECIDED
* story is workmanlike. Gets the job done, but not spectacular
* main plot is a railroad (following leads mostly), sidequests help
* character advancement is great for the most part, but there are some useless picks
* the bonus XP for melee takedowns ruins the XP progression (but this can be avoided with some self discipline)
* there are no melee weapons for some reason, only brawling takedowns
This was a good buy, I heartily recommend it. But be sure to make a master save when the first real mission starts to skip the intro on replays.