Telengard is an unofficial (as far as I can tell) version of the early and popular Dungeons and Dragons style game of the same name, that appeared on many 8 bit machines (Atari, Apple, TRS-80 Model 1/3, Commodore 64, PET, IBM PC and CP/M) by 1982. Daniel Lawrence (the original author) had been developing it since 1976 under the name DND for a PDP-10, bringing it over to microcomputers first in 1978 with the Commodore PET version. The company that made it, Avalon Hill (through their subsidiary Microcomputer Games) had been popular for decades with military board games, and did publish multiple games for the Coco (V.C, 3D-Breakthru, Shootout at the OK Galaxy, etc.), but this game was never officially ported to the Coco. The title screen says the game is copyright 1982 by Avalon Hill, but with Coco modifications by Ross Magerus of El Reno, Oklahoma. It is written mostly in BASIC, with some assembly language routines for handling the high resolution screen (particularly text drawing and scrolling), and also moves the graphics screen up to the end of RAM to leave 6K more room for the BASIC program itself.
The game itself is graphical with a top down view of the dungeon as you wander around it. You create your character attributes randomly (like rolling dice in real D&D and you have the ability to save your character and reload it. It also plays in real time, with things able to attack about every 5 seconds if you don't respond with keyboard commands. It has a wide variety of monsters (with different levels for each), extra things like altars, fountains, teleportation cubes, spell casting, etc. There are 50 levels and there is no final goal except to make your character as strong as possible. Probably the worst part of the game is how fast you can die; it is quite easy to get a too powerful monster right off the bat and die, ending the game. The BASIC graphics drawing is slow as well, but this affected other ports and not just the Coco.
I am not sure when this was released, but I know I had a copy of it on my Coco 1 back in the mid-1980's before the Coco 3 was even announced.
Telengard
Title: Telengard
Author: Daniel Lawrence (original PET version), Ross Magerus (Coco version).
Publisher: ??? (original by Microcomputer Games, a division of Avalon Hill Game Company)
Released: Sometime between 1983 and 1986
Requires: Color Computer 1/2, 64K RAM, disk drive.