Nice song in the video. I don't know much of Lynrd Skynrd, but I like that song. <img src="smileys/smiley2.gif" border="0" align="middle" />
To create a game using a grid, simply create a new game, then go the Layout tab and click on 'Toggle Grid'. Right beside it are two options to snap the grid according to what it is your trying to do.
You can also edit the vertical and horizontal sizes of the grid by clicking the 'Edit Grid' button right above the 'snap-to' options.
For a game like Geometry Wars though, I wouldn't select the snap-to options because they could possibly restrict movement of objects if your trying to move that quickly.