The game's artificial intelligence is impressive, both in and out of combat. In combat, enemies are cunning when given enough room to move around. Human enemies hunt you intelligently, using cover and the terrain to their advantage. Meanwhile, creatures such as packs of mutant dogs behave like you'd expect wild animals to. They attack when they feel they have the advantage but flee if given a painful lesson. It's this kind of behavior that makes the zone feel alive, with these different factions and animals all trying to go about their daily tasks. The AI does take a hit when placed in tight interiors, though, as the lack of maneuvering options makes it turn a bit predictable, but you'll likely appreciate this fact early in the game, as hiding inside a building and picking off the grunts as they come through the doorway is the only way that you'll survive some of the early battles.

So what kind of hardware power are you going to need to run this thing? It may not show off all the latest graphical effects, but this game is rather demanding. While it's by no means a top of the line rig, our Pentium 4 3.4 GHz, 2 GB RAM, and 512 MB Radeon X1900 system had problems at maximum settings. The game also tended to stutter quite often, sometimes pausing for three or four seconds at regular intervals, which occurred on two different Windows XP rigs at maximum visual quality. Though that isn't the best of news, S.T.A.L.K.E.R. does support widescreen resolutions, which should please many.