- Joystick: Use the 2-way joystick to direct the cannon along the bottom of the screen; it cannot wrap around from one side of the screen to the other.
- Firing Button: Use this button to make the cannon fire bullets up at the invaders; you can only fire one at a time but you shall never run out of them.
- 1 or 2 Player Buttons: Push these buttons to begin a one or two player game.
As in the original game, you shall control the cannon (which is now coloured turquoise instead of green), and must use it to destroy the space invaders' formation; direct the cannon left and right, to choose a position to fire from, then time your shots so that they arrive at the location of an invader that you are trying to hit. Use the shields to protect the cannon from enemy fire - but, be aware that both your (and the invaders') fire can chip away at the shields. Getting hit by any invader's bullets will result in the loss of one life; however, an extra life is again awarded at 1500 points by default.
The three alien invaders are now coloured magenta, turquoise and green (instead of white) but they still behave the same; they remain in formation, as they advance towards the bottom of the screen. The entire formation will move to the right or left until the far column reaches the side of the screen - then, the formation moves down one row, and returns to the opposite side of the screen. The lowest invader of every column will fire bullets down to the ground; if any one invader manages to reach the bottom of the screen, the game will immediately be over, regardless of how many lives the player has remaining. Starting from the fourth (second in the Midway licensed version) stage, there will be "gaps" in the formations, to accommodate the fact that some of the "medium" invaders shall split into two, when you hit them - and, it is also worth noting that the "split" invaders will look like this:
As in the original game, saucers, which are now coloured magenta instead of red, appear randomly over the formation; they appear on one side of the screen and cross over to the opposite side. During this time you can attempt to shoot them for bonus points - and the point value that is awarded again appears to be random, but it can be controlled to some extent by counting your shots. The second type of saucer is also a new flashing one, that can only be destroyed when it is visible; both types now also possess the ability to drop reinforcement invaders and make a stage last longer.