The player's ship is loaded with two flavours of weaponry: rapid-fire exploding-tip missiles, which suffice for destroying the various enemy ships; and the homing probe and stinger missiles. The red stinger missiles, which are useful for taking out bigger groups of ships, automatically lock on to the closest target in the player's vicinity. When launched, these missiles head for the locked target and detonate large explosions. On the other hand, the blue probe missiles are used for disarming the Drones at the end of each level. These missiles have built-in technology designed to decrypt the codes that guide the Drones. Once the decryption process is done, the probes gain control over the Drones' internal circuitry systems and do interaction akin to that of a "disarm" signal from the menacing alien mothership. The player's ship also has a shield which, once activated, will gain the player invulnerability to enemy fire. The shield has limited energy, though, and will not be reusable until a certain amount of time is taken for it to recharge.
Disarming a Drone will award the player 500 points, and the game will present you with praise from an unnamed officer. Accidentally hitting the Drones with any weaponry other than the blue probes, however, will result in a nuclear detonation killing the entire population in the current area. This will also sentence the player to a penalty of 1000 points off of his/her score counter.
The player's progress is marked using a heads-up display at the left of the screen which represents how many Drones you have disarmed or detonated via six icons. The Drone on the current level is outlined by a green box. Blue Drone icons signify disarmed Drones; red ones signify detonated Drones.
Preceding the Drones on every level is a boss enemy that can only be successfully destroyed using the red stinger missiles. Each of these bosses has a different form of protection against their weak areas, however, and must be shot at with the standard exploding-tip missiles before the stinger can be launched into the weak area. The only exception to this is the boss on level 2, the Gemini, which must be taken down by launching multiple stingers at both its left and right sides (the amount of stingers to be launched depends on the difficulty level).
If (and only if) all six of the Drones are successfully disarmed, the player has to face wits with the large alien mothership. The mothership has a rotating shield with doors that it can launch fireballs through. The player is vulnerable to these fireballs even when the shield is activated. When a red stinger missiles is launched into an open door, one of the mothership's engines explodes. This must be repeated two more times in order to completely destroy the mothership and win the game.
Ryan Alexander (49)