Audio Spectrum Analyzer is a ROM cartridge that allowed one to play audio cassettes through the cassette port, while displaying the equivalent of an EQ based on the sound coming through. While not technically a game, it did have some 'entertainment' modes to it, such as a kaleidiscope mode that followed the music, which is why I am including it here. It was, I believe, Steve Bjork's first program that was sold through Radio Shack, except for possibly Popcorn.
NOTE: It came to the Coco community's attention recently that a revised version was release several years later that ran using PMODE 3/4 graphics that would run properly on the Coco 3. The manual was not changed, but several copies of the cartridge have now been found with this later version.
Title: Audio Spectrum Analyzer
Author: Steve Bjork
Publisher: Radio Shack (Datasoft)
Released: 1981
Requires: Color Computer 1,2, 4K RAM, cartridge.
Note: This program will not run correctly on a Coco 3, due to the fact that it uses a semi-graphics mode that does not exist on the GIME chip.