In “Atari 2600 Base Attack,” players control a UFO with the mission to annihilate cities beneath it. Movement is unrestricted, allowing flight in any direction, and attacks are executed by holding the button down and directing the assault. Defensive cities retaliate with missiles aimed at thwarting your efforts. As the game progresses, these missiles evolve into balloon bombs that pose a collision hazard, and in further stages, these bombs transform into horizontally moving missiles when aligned with the player’s altitude.
The game features four distinct modes. The first two modes cater to either solo or duo players at the beginner level, while the third and fourth modes offer solo or duo gameplay at an advanced level, respectively.
Progression to subsequent levels is contingent upon the complete destruction of all cities within the current level. The game concludes either upon achieving a score of 999,999 points or the loss of all player-controlled ships.