From Wikipedia:
Druid is computer game for the Atari 8-bit family and Commodore 64, also ported to Amstrad CPC and ZX Spectrum, published by Firebird (Telecomsoft) in 1986. Graphics and design by Dene Carter. Code by Andrew E. Bailey. Music by David M. Hanlon.
The player plays the part of Hasrinaxx, a druid who is trying to rid the world of the evil Acamantor and his army of demons. To do this, Hasrinaxx must travel through several levels. The first level is a normal landscape, and the ones after that are underground, each one deeper than the previous. Each level is infested with various enemies such as ghosts, giant insects, and even demons. Hasrinaxx can shoot these enemies with three different weapons: water, fire, and electricity, but they all come in a finite supply and are not equally effective on all enemies. Hasrinaxx can also summon a Golem to help him, or turn invisible for a brief period.
The game was sequelled by "Druid II: Enlightenment" and "Warlock: The Avenger"
Source: Wikipedia, "Druid_(video_game)," available under the CC-BY-SA License.