The control scheme is iconic for its shared-keyboard setup.

A humanoid figure composed entirely of flames, Fireboy is characterized by his reddish-orange hue and confident stance. He is immune to lava and fire, able to walk through pools of molten rock without taking damage. However, water is his Achilles' heel; a single splash of blue liquid extinguishes him instantly. He is often seen as the "grounded" character, capable of traversing dangerous volcanic floors.

Perhaps the most unique mechanic introduced in the series (specifically in the Light Temple ) is the mirror and beam mechanic. Players must rotate mirrors and refract light beams to trigger sensors and open doors. This added a layer of logic-based problem solving to the platforming. It wasn't just about jumping; it was about geometry and physics.

Both characters are destroyed by contact with black or green toxic puddles.

The premise of the series is deceptively simple: you control two characters simultaneously (or with a friend) to navigate through ancient temples.