Help With Categories

Hi ,
I am new to all of this wordpress stuff and have been attempting to create an arcade site (http://gamecrash.co.cc). The problem is when you click onto a category all of the games decide that they want to show themselves. I am wondering if there is a way to just show a small thumbnail with a description next to it that links to the actual page and then loads the game content.
Any help would be great :-).