Offender is one of the earliest Coco games that was based on the arcade smash Defender. It features the same radar, humans to rescue, and features sideways scrolling terrain similiar to the original. This was one of Greg Zumwalt's earliest efforts for the Coco (and, I believe, his first machine language one), and from before he programmed for the Coco exclusively through Radio Shack/Tandy.
Title: Offender
Author: Greg Zumwalt
Publisher: American Business Computers
Released: September 1982
Requires: Color Computer 1,2,3, 16K RAM, tape or disk, joystick.
Download OFFENDER.ZIP. This contains the offender.dsk image. To run, type LOADM"OFFENDER", and then 'EXEC'.