To celebrate the release of the Spy/Sniper update, Valve has made Team Fortress 2 free to play this weekend. Should you be moved to buy the game this weekend, you'll end up saving some money.

Purchasing TF2 through Steam will cost $9.99 instead of the usual $19.99. Like the free weekend, the offer probably lasts until Monday. It's a good deal but if you don't own Portal or Half-Life 2, you'd be better off just buying the Orange Box compilation for $29.99.

The new TF2 update went live yesterday and adds new unlockables and Achievements for the Sniper and Spy classes. It also includes a new Payload Race game mode and four maps.