Tougi-Ou: King Colossus ("Arena King: King Colossus") is a Japanese Mega Drive exclusive game developed and published by Sega. It follows the adventures of a player-named protagonist who is initially sent to a cave to look for a stolen sword, and eventually gets embroiled in a quest involving his missing identity.
The gameplay is all in real-time, as the protagonist fights through rooms of monsters and obtains experience points. Extra levels increase max health and other stats, and the hero can find useful items like healing or new gear. Monsters will also drop bombs and keys: both used to create new paths deeper into the current dungeon.