Alien Revenge

This is a sequel to Alien Attack. The Aliens are back and they are intent on destroying the colony! Since the last attack, you have constructed a planetary shield defense, but they have discovered the orbiting power station that controls your planet's shield. You control the power station's lasers that will defend the station. You can fire in 8 directions with joystick. Once again time is important, you must defeat each wave within 40 /25 seconds (difficulty B/A) because your station must recharge its power supply. Also, your station cannot withstand more than 10/7 hits per wave (Difficulty B/A). Defend the station by destroying the aliens. You can also shoot the alien missiles. You have a shield which can be activated every 4 seconds by pressing the button. You have unlimited shots, but placing TV Type switch to B W limits shots to 40 per wave! You have 2/1 shields per wave and cannot fire while shield is on. If you can survive 99 waves you have defeated the attackers.