If you havent played TF2 before you can play for free this weekend.

http://www.steampowered.com/goldrush/

Valve has released a major Team Fortress 2 update including the new "Gold Rush" map and "Payload" gameplay style, with new weapons and achievements to earn the new weapons for the medic.

Some of the achievements look achievable, a lot look impossible.

Check It Out.

Sounds great, I only wish Valve would support the consoles too, TF2 on the 360 is dead.