There is no conventional crosses, "halfbara" counter number of cartridges in the store and things like that.
Instead of all this is thought aspects such as:
aiming through the fly;
fire regime change;
realistic defeat soldiers from weapons (just one bullet in the head or torso);
the possibility to deviate to the side for sniping and more.
Realism has happened forces act accordingly: run from cover to cover, once again not to be put out and not yawn at the risk of being shot by the enemy will take you longer, and so on. N. It is worth noting that there is half the battle as never before - teamwork.
1. You need to download and install Steam http://steampowered.com/download/SteamInstall.msi
2. Go to your account or register a new one.
3. Next, you need to follow the link received after purchase, log in under your account Steam and take a gift to yourself in the library or add to your inventory.
4. After activating the game appear in the library or in your inventory where you can already start to play or activate later / give to a friend.