Description:  Rock Grid Rumble is a racing game and this game instruction is from www.t45ol.com. The objective of the game is to have more rocks of your own color than your opponent’s when the match ends. Use the mouse to aim and fire the cannon on your turn only. Some locations on the grid cause something special to happen. Hover over these markers with the mouse to see what effect each symbol represents. The match ends when one of the top two grid markers is occupied.