Try to match rows of three to eliminate skulls from the playing field. Try to match rows of four to get a Skull Bomb. A Skull Bomb can destroy all skulls touching it when it lands. Match five to get a Mega Skull Bomb. A mega Skull Bomb will destroy all skulls near the bomb when it lands. Match two rows of five to get an Ultra Skull Bomb. An Ultra Skull Bomb will destroy skulls within a large radius of the bomb when it lands. As you progress the background will change and the curtains on either side of the play area will constrict, allowing you less space in which to setup combos. Also, new skulls will be introduced every few levels.