Polaris is the closest (in game play) clone of the arcade hit Missile Command that the Coco had. While the graphics were changed somewhat to represent subs at sea protecting islands (as opposed to the original missile silos protecting cities on land), this is the only Coco version that I know of that actually enabled you to pick which of the 3 bases you could fire from. It also included the smart bombs from the original, and they get WAY harder to kill the further up the levels you go. The game also goes through the entire 8 color palette of the Coco 1/2, enabling you to have night bombing and other effects (you get them in sets of 2; and they go through in palette order). As you progress, you also get many more waves of missiles coming at you, and missiles that split into multiple missiles on their way down. A very well done version. The game shared the joystick (for positioning where you are firing), with the keyboard (3 different keys to match your subs), and featured two sets of keys... so in a 2 player game, each person would be on a different side of the keyboard.
Title: Polaris
Author: ??? (likely Robert A. Arnstein) (Device Oriented Games)
Publisher: Radio Shack/Tandy
Released: November 1, 1981 (originally scheduled for November 30, 1981)
Requires: Color Computer 1,2 or 3, 4K RAM, cartridge, joystick or mouse.