The game delivers what it promises, but not much more than that.
Sadly, I was wrong...
Now, don't get me wrong here, the game really is a blast to play, but it is completely linear, everything is scripted and after you're done with the game once, that's it.
The game adds a metric ton of innovative stuff, those little things that you see and say "Hey, that's cool." For an example, when you go to the surface and have to equip a gas mask, after a while when the filter on the mask starts to jam up you start to see little drops of water on the glass, and then it spirals until you can barely see through the glass.
The campaign in the game is relatively simple, you're traveling through Moscow trying to stop a terrible evil from annihilating the human race, during which the game splits into three types; 1. Tunnels filled with mutants and bandits. 2. Surface filled with mutants and bandits. 3. A quick stop at a station where you restock and resupply. After awhile it starts to just be a loop of buying ammo to get through the next 'stage'. To me, that kind of ruins the storytelling, to which I really enjoyed.
All in all, not quite worth the full price tag, but overall a awesome game. Let's hope the next one has free roaming.