Kingdom Crusade is a strategy game for the Game Boy set in a fictional medieval fantasy world where players can align with either a dark army or a light army. The game features real-time combat with an emphasis on action, requiring players to defeat enemy units or capture castles to secure victory. Each army's units are balanced, and battles unfold in a fast-paced, arcade-style format.
This video game takes places during a hypothetical apocalyptic battle between a dark, evil army and a light, good army. Even the king and queen of each respective kingdom is expected to contribute to combat duty; which was expected of kings in the Middle Ages but not of most queens.
Even though this game is medieval in nature, it does not depict any culture of Medieval Europe against each other. Players can take either side and both kingdom's units are of equal strength to each other. The units in the game correspond to Western high fantasy (i.e., paladins instead of samurai). All fighting is done in an arcade manner (real-time with button mashing) rather than a typical manner of a strategy or role-playing game (either turn-based or real-time without button mashing).
Each player must either destroy all of the opponent's units or capture all the castles in order to win the game and to defeat his or her opponent. Winning results in a celebration screen while losing is the equivalent to a game over.