There is no TRS-80 cover art on file for this game
This is a dungeon crawl game - equip your character, enter the dungeon, fight monsters and win treasure; traps abound as well. Many events are random. You can save your character (assuming he survives) to use in later episodes.
Balrog was a 'sampler' of the Maces and Magic series, with only the later ones being full games.