Quest Fantasy Challenge is a Mr. Do! variant where Brian, the hero from Quest 64, must navigate through levels by collecting all crystals while avoiding monsters with deadly touch. The whole screen is filled with dirt that can be removed by simply walking into it, creating a path for the monsters to follow. To progress, Brian needs to clear a safe path and defeat the enemies.
Gameplay involves using Brian's magic staff, which shoots powerful blasts but needs time to recharge before use again. Alternative weapons are available in chests scattered throughout the levels, some of which can be defeated by digging under them or hitting their heads with the staff. Power-ups like increased speed and firepower also await discovery.