Warlock is based on the 1989 movie of the same name.
When the sun aligns with the moon once every millennium, druid guardians summon their magic of their runestones to prevent the rebirth of the Warlock. The runestones are scattered through time and across the continents and you must find them before the Warlock does.
The gameplay is simple. You go through different stages fighting off creatures and then finding the runestones. You fight off enemies by simply blasting them with this energy, using this orb you have with you, or you can use a spell to kill them. There are some puzzles in the game too. Some of the battles with the tougher enemies require some strategy to defeat them.