An alien mothership is protected by a shield that you cannot shoot through. As the mothership approaches it releases wave after wave of alien attack ships that will bounce around until you have shot them down or are killed by colliding with them. After you have conquered each wave the mothership moves closer making the goal of survival harder. Occasionally a rotating orb is released - shoot this to temporarily disable the mothership's shield and shoot the mothership. After enough hits, the mothership will retreat.

Player movement is controlled via a virtual joystick or by moving your device. Touch the screen to fire.

Use power ups to help you get through each wave.