Cannonball Crisis is a puzzle game. The aim of the game is to clear all the cannonballs at the top of the screen by firing up a cannonball of the same colour to create a touching group of three or more.
Sometimes the cannon will be loaded with rocks and these can only be gotten rid of by firing away the balls which support them. Rocks turn any cannonballs they touch to rock so be careful.
Occasionally, the letters B, O, M, B will appear as balls. Fire these together to make the word 'bomb' and you'll get a bomb which you can fire at any ball to remove all balls of that colour.