Background
Team Fortress 2 is a class based multiplayer shooter developed by Valve for quite some time now. Over the development, Team Fortress 2 has switched a bunch of different styles, and ended up with a comical looking game, that satires on the whole FPS genre.The Good
The game heavily relies on team work. It has wave respawns which encourage the team to work together to achieve a goal. This is good because even if the team does not work cooperatively, they are still spawning together.The nine classes in the game are excellently well balanced, each one has its own distinct strength and weakness... and it is almost impossible to perfect skills in one class because there will always be a weakness to it which another class can overcome.
Team Fortress 2 makes satire of the FPS genre in extremely clever ways. The characters even interact with each other through voice and animation, and the player isn't even aware that he is projecting the animation. Though this doesn't sound like much it certainly adds to the overall feel of the game, and the level of polish put in it.
Finally, there are loads of players in team fortress 2, and I mean loads.. on the PC, the xbox 360 version is a different story... :-(
It is also important to mention that valve keeps the game alive by adding updates and achievements every now and then. These achievements keep players coming back.