F.E.A.R. will make you pee your pants, but also make you come back for more.
Graphics/physics:
By 2005's standard, the graphics of F.E.A.R. is pretty damn amazing. By today's standard, it is still pretty good to look at. There is a palpable attention to detail in the background and other objects, and since I played it on a rather high-quality graphics card it doesn't lag at all. I cannot guarantee that this will be the same for your computer, but for the most part the graphics shouldn't be too demanding to your PC. The physics is wonderfully realistic. The way paper rips to shreds in the air then solemnly glide down on the ground and the way that glasses shatter both obey real world scenarios as well as contribute to creating a very scary atmosphere.
Gameplay/plot:
I know I said this already but I have to reiterate: F.E.A.R. is the scariest game I have ever played. At a glance, the fact that you are fighting a bunch of cloned soldiers doesn't sound all that terrifying, but they are your source of action rather than fear. The real horror sequences appear mostly outside of battle. This game does not have cut scenes except for the beginning of game, this allows you to be more immersed in the game universe, and this makes the horror sequences more effective. Many times you feel that there are things that signal you something icky is going to happen, like statics in your walkie-talkie from unknown origins, but there really isn't. The developers really manipulate both shock and terror factors masterfully in the game. In other words, they never use the same trick twice.
The action sequences, although intense, are actually relieving, because combats are the only moments when the game stops scaring you. Aside from that, battles are incredibly fun to play. You are up against one of the most intelligent A.I. ever designed. Your foes will tirelessly try to flush you out of your vantage point. For example, you might think that hiding behind a corner and interchange fire with the enemy is a safe move. WRONG! Before you know it, there will be a guy sneak up behind you and, quite literally, bust a cap in your ass. The A.I. seems to be able to analyze your strategy and act accordingly, so you have to be constantly on your toes and be able to improvise at a moment's notice. If that is not realism, I don't know what is. Nevertheless, for some people this can be a bit frustrating because the A.I. is so smart and that after every respawn they will approach you differently, but that just prolongs your game time and increases the satisfaction once you finally overcome a stage.
As for the story, F.E.A.R. is also much more than meets the eye. Many might think that the developers simply ripped off a Japanese horror icon, Sadako Yamamura, or the creepy little girl, and put her in a shooter game. Although in an interview the designers admitted that the idea is indeed highly influenced by the Japanese horror stories, the plot itself is actually exceptionally original and absorbing. Through out the game you will encounter multiple phone messages that are never heard, and they usually document the dark secrets about what is going on. This plotline can probably turn into a pretty good movie if conveyed properly.
Multiplayer:
I was too busy playing single player campaign.
Fun ways to play this game:
One thing I did was I invited one of my friends to sit next to me and watch me play the game, and when I get too scared to proceed, he'd take over and play, and vice versa. It was a very fun experience and there were several instances when we both screamed like little girls.
If you get too scared to keep going in the game and no one can take over and play for you, I suggest you turn on some music on the side of your computer. It is amazing how much "Don't Worry, Be Happy" can help you when you suspect something wrong is right around that corner ahead.
Conclusion:
F.E.A.R. should take its place as a classic in the genre of horror shooter. Its brooding horror and intense action will indeed make it a timeless game.