The story of King Colossus is simple: you are a young fighter who lives in a small house somewhere on a fantasy continent and who was raised by the local wise man. Now, when he became skilled at sword fighting, the wise man sends him to the dangerous South Cave, to defeat the monsters populating it. By visiting different places, the hero will battle even more fearsome monsters, until he finally challenges the ultimate evil.

King Colossus is a top-down action role-playing game. You fight monsters by equipping weapons and swinging them in real time. There is a variety of accessories and items to find in the game, as well as different obstacles to overcome in the dungeons.