ABM: Anti-Ballistic Missile Game

An early Missile Command clone which puts the player in charge of defending the US East Coast from a nuclear attack. Enemy warheads rain down from the sky, targeting six cities (Boston, New York City, Philadelphia, Baltimore, Washington and Richmond) and the five anti-ballistic missile bases positioned between them, commanded by the player. The central, leftmost and rightmost launchers are equipped with standard 1-kiloton missiles, while the other two sport 5-kiloton ones that produce larger blasts.

Incoming missiles are destroyed when caught within the ABM's blast radius, and some of them may explode in a fireball of their own, setting off a possible chain reaction (which can be taken advantage of to save shots). Especially dangerous are the MIRVs, which in mid-flight release their payload of additional warheads aimed at multiple targets. The game is over when all six cities are destroyed, and the final score awards both ammo conservation and the number of incoming missiles intercepted.