Clear out as many colored blocks as possible . Blocks of same color that are adjacent disappear. Clicking on the blocks removes them and the rest fall down. Columns shift left when they are empty.
Game is over when there are no moves left or no blocks.
I've got some ideas now that I have more time. Wow, long time since updates. I've reset the scores, and I'll be graduating soon. So this web site will go down within the next semester. I'll change the host to something more permenant.