Castle Quest is a strategic game for the Game Boy that combines elements of board strategy and card-based combat. Players command a diverse army of fantasy units on a chess-like grid, aiming to defeat the opponent's king. When units collide, battles occur using a playing-card roulette, where each unit's health and card abilities influence the outcome. Players can also cast spells to damage enemies or heal allies, adding depth to the gameplay.
Castle Quest is board strategy game mixed with magic battle confrontations. The game is like a chess clone with fantasy creatures that fight with playing cards. The player's goal is to topple the opponents king. A player controls a small army (with units like orcman, karate man, warrior etc) on a small chess board. If two pieces meet on the same square, they fight on special screen with a playing-card roulette. Depending on the cards that each unit gets they will do damage to an opponent. Different units have different health points and also different cards, for example, some units have more propensity to getting the instantly killing joker card.
Some units are able to cast attack or defense spells. When these pieces move to an empty square on the map a spell window will open. Each spell can either damage surrounding squares or heal/revive surrounding units.