Like with most Invaders games, the player controls a ship at the bottom of the screen that must shoot overhead enemies (Martians) that move in formation(s) that fire at the player. Bonus saucers fly at the top of the screen that are worth much more, score-wise, than the Martians. The player can take cover behind several shields for protection against enemy fire. Getting hit by a direct enemy missile will destroy the player’s ship and the game will end when there are no ships remaining.
There are many differences when compared to most Invaders-type games, however, such as the player’s ship can shoot many shots at once, rather than only one at a time. They can also withstand a mild hit without being destroyed and their ships consume energy (which is displayed at the top right) with every time the player fires; however, energy also gets replaced when the player does not fire for a short period and whenever they destroy a Martian or ship (which the latter replenishes a larger amount of energy as compared with Martians). A bonus ship is awarded with every 5,000 points scored.
There are also six bunkers (on the easy difficulty setting) – a large amount in comparison with most Invaders games – which will disappear altogether after being shot too many times, rather than slowly disintegrating like with most Invaders games. They also do not get replaced with each new wave (which is also usually the case with many Invaders games).
The Martians themselves will not only exude a large amount of firepower, but their shots are also pretty quick as compared to most Invaders games in general. They can also move in as many as two independent groups, bobbing up and down and not dropping down closer and closer to the player’s ship in formation like with most Invaders games (plus the player cannot be “invaded” either by having an enemy land on the ground and end the game). There are also three types of bonus ships that appear: a rocket at the top of the screen, a purple ship that flies fairly close to the player’s ship, and a large yellow ship that is also in close proximity to the player. Although the rocket doesn’t fire, the purple and yellow ships do, the latter of which drops a bomb that explodes in a fairly wide horizontal arc.
The game has three difficulty levels to choose from, being easy, medium (with point values being triple the amount of easy mode, there are only four shields and the player is only given two ships to begin with, rather than three), and hard (with point values being five times that of the easy setting, there are only two shields and the player starts a game with only one ship).
The player also has the ability to choose between either a low or high graphical display as well.
- Move ship–mouse
- Fire–left mouse button
- Rockets and purple ships always appear from the left side of the screen and travel right, whereas the yellow ships always appear from the right side and travel left.
- With every cleared wave the background scenery changes.