Long ago, even before ST Format, there was an innocuous little game called Druid. Millennium obviously liked it very much because they've taken the eight original levels of the game, designed another eight and put all sixteen out as Warlock The Avenger.
Every set of levels represents a tower. You begin at the top and work your way down, eventually destroying the demons that inhabit the last four levels. In between, there is plenty of monster-bashing, chest-opening (not in the Alien sense) and wandering about for you to do. In the chests, you can sometimes find helpful spells - water, fire and so on. If you're lucky, you can also find a rather useful Golem who aids you in your quest.
You don't need keys for the chests but trying to get through a gate without one is a waste of time. Pentagrams here and there enable you to refuel with energy. And, er, that's about it.
There's little to distinguish this from the 8-bit versions of the game. Graphics are extremely mediocre - the sprites aren't particularly well animated and they move across bland backgrounds. The chest screen is nicely drawn, though. Sound? Just the odd spot effect.
At a budget price, you might be less miffed about buying it. As it stands, it's fine for a five minute blast but no good for serious gameplay.