Lunar Lander was, as far as I know, Greg Zumwalt's first commercial game for the Coco, and the first game for the Coco from American Small Business Computers. It is also the only one that he wrote in BASIC, versus machine language. It may also be one of the first commercial 3rd party games for the Coco period, having been released only 8 months after the Coco's launch (it was done being programmed on Feb. 12, 1981, as shown on the credits screen above).
As with most Lunar Lander games, you're object is to land safely on a flat surface by controlling your ship's angle and rate of decent, with a limited amount of fuel. This version adds a few quirks, like dying if you hit the edge of the screen, and their are some meteors moving across space that you also have to avoid.
Title: Lunar Lander
Author: Greg Zumwalt
Publisher: American Small Business Computers
Released: around June 1981 (program completed Feb. 12, 1981) 1st advertised in 80 Micro June 1981
Requires: Color Computer 1/2/3, 16K RAM, Extended BASIC, joystick.
Download lunarlandergz.zip. This contains the lunarlandergz.dsk image. To run, type RUN"LANDER". Use the joystick to control thrust and direction.