Cavelon is an early colour arcade game from Jetsoft and was first released in 1983.
It is a highly frustrating and difficult maze game where you are a knight and must find pieces of a door to make your way up to the next level of the castle. The pieces are hidden in a simple maze and are guarded by enemy troops.
You can shoot, surprisingly, although the firing system is a bit tricky. The bullet will only stay on screen until you press the first button again. So you can effectively accidentally cancel a bullet (by shooting another one), just before it hits its target. So you have to be careful.
Enemies abide by the same rule, which evens things out, but it’s still very difficult getting the timing right. To cap it all: there’s a timer, although it’s not entirely clear to me exactly how it works. You have a kind of ‘smart bomb’ weapon (The Magic Sword) that you can use a small number of times per level, and temporarily clears the screen of all chasing bad guys. You can also pick up more magic swords as they appear.
Cavelon is one of those old, ropey arcade games that hardly anyone cares about. Show it some love and play it, if you can find a copy.