Colony 7 © 1981 Taito.

The player must defend Colony 7 from alien attack by either using the main weapons that fire shots, a Mega-Blaster which knocks out targets near the detonation zone, or with the Eradicator that acts as a smartbomb which clears the entire screen. There is an ion shield which provides temporary safety for the colony below, but can be blasted away by alien fire.

Colony 7 is in many ways a combination of two of the most popular shoot 'em up games of the time, containing elements of both Tehkan's Pleiads and Atari's Missile Command. The main innovation of Colony 7 was the extended weaponry arsenal. This gave the player the choice to change between several different weapons, with the the Eradicator needing to be purchased separately as "extended weaponry".