Since I did the pre-order thing from value, I figured I'd check this game out.. It's really pretty good.As a special bonus, those who pre-purchase The Orange Box via Steam will also receive a copy of Peggle Extreme. PopCap and Valve have teamed up to create a special edition of the game cited by MSNBC as one of the “Top 5 Most Addicting Games of All Time.” This first ever collaboration is themed around content from Half-Life 2: Episode Two, Team Fortress 2 and Portal which will positively result in Extreme Fever.
It's sortofa pinball machine. The ball comes out of the thing at the top/center of the screen - you rotate it around with the mouse then click to launch a ball. When the ball hits a block or a sphere, it bounces away (and bounces less forcefully if it's something you've hit before) and you get points. Once the ball drops off the bottom of the screen, the things you hit vanish. Get all the orange ones gone and you move to the next level - run out of balls (left side of the screen) and you have to start the level over. There's also various bonus things for points and improved aim and such.
Certainly worth a try if you're pre-ordering the Orange Box (10 levels or so for free) and, IMO, worth the $10 for the full version.
Can also find the demo, which may or may-not be the thing that comes with Orange Box pre-orders, here: http://www.popcap.com/games/peggle .