An awesome game that will keep you playing for Hours . . .
The gameplay is extremely fun to play or even mess around in with all the cheats and mods that you can use. The physics in the game is superb, sometimes you can to use the physics engine to get through areas. The enemies AI is terrible but is also fun to kill and fight against.
The graphics, for its time, were absolutely amazing. The water effects and reflections in Half-Life 2 were awesome. All the environments fit into the game and storyline making the game even more sweet to look at. The particle effects from the walls to teh blood splatter is the best I've seen to date.
The sound is great, from the weapon sound effects to the creepy zombie sounds is just great. The zombie infested city had creepy music which made the games atmosphere even better.
Overall, its an awesome game, certainly not like Half-Life but it gets close, real close. I recommend that if you are a PC gamer or even an Xbox gamer, get this game. It is certainly worth the price.