Highly addictive game, probably the best multiplayer game out there.
It uses the source engine so it has great graphics. One of the best on the PC for sure.
Gameplay: 10/10
Great guns to choose from, great maps, and just plain fun. This game is just pure amazing. The hitbox is amazing. Not laggy at all. No problems whatsoever really to be honest.
Lasting Appeal: 10/10
The mod community is huge. You can find custom maps and things such as gungame and zombie modes are great. There is also a whole lot of skins for weapons and people and hostages. Great mod community. Great skins for guns. If you don't like a gun, just get a skin for it. Also, you can find redefined versions of the guns in the game except it looks HD which is great.
Overall: 10/10
Nothing really wrong with this game. It will definitely go down as one of the best multiplayer games and just a game in general in gaming history. If you don't have it, buy it. It comes with a pack of Half Life 2 Deathmatch and Day of Defeat Source.