This game is an absolute BANGER!
There is so much awesome to say about this game and how it's amazing in every aspect from the overall appeal and style to visual effects and soundtrack, It's amazing that you're allowing to access this for free as it's definitely in a quality for a paid game.
The only request/problem I had was that at higher resolutions (lower FPS) the controls became a bit sluggish ,although lowering the resolution helped, it would still be awesome to have an option, to turn off the mouse smoothing - as it gives a bit of a floaty feeling and makes it quite hard to aim.
I loved the way the soundtrack intensifies once you kick in a door with enemies - really puts you in the action mode!