Playing most shooters doesn't really train you for this one. You're inclined to hide behind cover, place headshots. That's the wrong move. Do not conserve ammo - it's falling out of everyone's orifices. Shoot everything that moves and THINGS THAT DON'T - environmental kills are the name of the game, and there are few 3D assets in the game world that don't explode if they're shot.
It has the unrelenting misery of the original, in a new setting, and my favorite thing - no more pixel-hunting. This time, there's a button that makes sure you don't overlook everything on screen that's clickable, which is hands down the best quality-of-life improvement of any adventure game.