Gandalf the Sorcerer (1984)

Gandalf the Socerer is a single screen shooter viewed from behind the castle walls looking out into the land, where you play the role of Gandalf and you must protect your castle from attack by Lizardmen trying to get your treasure. Gandalf starts on top of the castle walls and tries to destroy the Lizardmen who appear from the woods and move towards the castle by moving a crosshair and blasting them with fire. Any Lizardman destroyed leaves behind a gold coin.