A unique shooter that shines for being great, and then earns extra-credit for being different.
Setting the game in and around Chernobyl in the Ukraine pays off in spades: the land is foreign and mysterious, and yet familiar from history class. Due to the "zone" - an area affected by pockets of radiation and anamolies that can rip a dog in two - the ground and buildings are burnt-out, grey, dilapidated, and generally in ruins.
The fighting is where this game lags behind others. The guns are weak in the beginning, the enemy's flank and use cover exceptionally well, and most people wear body armor. My fps experience not-withstanding, I set the game on "novice" and still found the ending maps to be exceptionally difficult. The game could use more allies, as these were the parts that really shone for me. Trekking through Pripyat with five other stalkers was one of the highlights for me; until they stopped half-way to my goal and said, "good luck!!"
Probably the best thing about this title is the sheer number of mods out there to tighten the textures, improve lighting, etc. I personally choose the "Stalker Complete Mod 2009" for my playthrough, and immediately noticed a visual difference.
Along with Crysis, this game is a clear example of Eastern Europpean developers schooling the over-polished but bland titles of the west.