Desolate wastelands filled with mutants and power-hungry clans fighting for survival; you're dropped right in the middle
Graphic stability has been improved upon over S:SoC, as well as the AI. You see much less, if any at all, of NPCs ignoring you if you're littering them with bullets. The one drawback to the AI is the precision accuracy they have with grenades. You could be 30 yards away, hiding in the top of a house with a busted out roof, working on picking some bad guys off when all of a sudden your grenade warning symbol pops up on your screen...by then it's too late, the grenade goes off just as it hits the ground and you're dead.
Even with all the patches released for STALKER: Clear Sky (S:CS), there are still bugs that riddle some of the non-essential game play. As you traverse through the game you eventually get to a point where you can join any of the factions: Duty, Freedom, STALKERS or Bandits. Just as long as you don't piss off any of these factions before you try to join their ranks. Upon joining them, you are more or less tasked into trying to expand your factions power hold on the wastelands of Chernobyl. However, once you do go about clearing out your enemy faction that you're at war with, you're own faction members never show up to hold the ground like your PDA indicates is going to happen. A bit more work is needed on the faction wars aspect of the game to truly make it well worth anyone's time to assist their faction.
The ability of having to risk your life to flush out anomalies with your tracking device is much more entertaining to me, then to just find them dancing around on the ground like you did in S:SoC. The weapons are a bit better then S:SoC offered and the ability to upgrade your weapons greatly improves upon helping you out, especially towards the start when your weapons and armor are a joke.
The side missions (they're more like annoying tasks) you can pick up from some NPCs as you play along get tedious and repetitive. You have to go find some item on a dead NPC, deliver weapons/ammo/medkits or help clear out a way-point that's overrun with mutants or non-friendly NPCs. These tasks are easy ways to make some extra cash to help fund your upgrading, but that's about all they're good for. You seldom find anything worth while for keeping.
The storyline is kind of short and quite easy to run through in 6-8 hours. I think that S:CS fits in well with leading you into how things became to come as they are in S:SoC.
I'd have to say that my greatest enjoyment out of this game is the ability to join factions and fight for them to expand their territory. When you join different factions, the difficulty of future exploration in S:CS can get easier (like joining with the STALKERS, only the Bandits truly hate you) or it can get much more difficult (like joining with the Bandits, then almost everyone dislikes you). With some more work on hammering out bugs with the faction wars, things would have been even better and I could have spent more time playing around with that aspect of the game.