This game is a bit dated, punishingly difficult and glitchy (pre patches), but with a little patience it can be great.
Having said that, S.T.A.L.K.E.R. is a fun game with an eerie atmosphere, challenging enemies and great ambitions. It has something most shooter lack nowadays, heart, and because of that it should be enjoyed by anyone with any interest in a game so dedicated to realism it won't hesitate to kill you with one headshot.
Welcome to the zone, a man made nightmare where mutated monsters thrive and groups of soldier mercenaries known as stalkers aptly fight for their own agendas. Some hunt for the artifacts the zone regurgitates, while others seek to destroy the zone. The intro to S.T.A.L.K.E.R. is vague at first, and it does have a hard time connecting, especially if you don't ask questions or go through all the conversations. You play as the 'marked one' a stalker who falls out of a 'death truck' truck and is promptly rescued. Now you get to pay of your life debt while regaining your memory and hunt down a stalker name strelok.
Gameplay is realistic, and as such it is very, very unforgiving if you take a lot of chances. Your character tires, succumbs to being weighed down by equipment, attacked by bandits and mutants, can suffer from radiation poisoning, be killed by anomalies, bleed to death, and suffers from a receding hairline. The name of the game is caution; since you don't get decent protection until later in the game, cover is important. It's not wise to wander too far from the intended goal, but it might pay if you find supplies. There are dozens of missions to do on the side for cash and goodies, as well as a wide variety of weapons to bring the pain with.
The atmosphere, while showing aging from it's starting date, is still generates a good deal of tension. Wind and rain make the emptiness of the zone feel unsettling, while lighting makes you keep on guard for mutants and stick to traveling by day. It's hard to trust people in the zone, as many only serve their own ends, and bandits don't hesitate to kill on site. You get plenty of abandoned buildings to view, as well as plenty of underground moments and forest fights for viewing. Some mutants are well hidden, so it pays to use your ears as well
The game's major flaw is it's glitches, which as are numerous, but by no means make the game unplayable. As stated by dozens of loyal fans, patches and mods offer plenty of opportunity to help make up for this shortcoming, but the fact that glitches are present is still worth noting. It's nothing too serious, but between the game glitches and the challenging realism frequent saving is advised.
The game spans 30 kilometers and has plenty to shoot and even more to find. Pacing can be a pain, but you're never set back by the inability to get anywhere and there are few unavoidable fights that don't tie into the plot. Consequently you can find hours of fun from this game, and with several endings a wide array of paths to take, and dozens of mods to sample, the replay value is great. S.T.A.L.K.E.R.: Shadow of Chernobyl isn't a must have, but it is worth while.