Despite their efforts, fireboy and watergirl remain trapped in strange temples. They must figure out how to solve the problem and escape by cooperating. When playing alone, you can move each character individually or try to move them all at once. However, the game is much more enjoyable when played with friends or siblings dressed as different characters.

Fireboy is immune to fire, so he can freely walk through the bubbling lava pools, but be cautious when entering the water. At each temple, boys and girls must run and jump between fire and water. The water girl can survive in puddles, but she is injured when she enters the lava. Sharp objects on the road should be avoided by both. Each level's goal is to reach the temple doors that lead to the next room. If you are in the Water parity, bring a blue sign to the door, and a red sign if you are in the Fire parity. Both characters should look for their own color of gem as they travel. Your score and rank will increase faster as you get closer to the door at the end of each level.

You must press the buttons that activate the elevator, the push box, and the brick that will assist you in ascending. To find the solution for each level, you must also change the switches.

However, the game is more than just running and jumping over pits of death. You'll need to work together, with one character holding down switches or platforms while the other passes. Finally, you'll need to figure out how to reunite the two characters. Some stages simply want you to get through them as quickly as possible. Everyone will advise you to move both heroes simultaneously. Some people will not let you leave until you bring them something special. At the end of each section, you'll be given a score based on how well you performed. If you want to improve your score or your ability to use water and fire, you can replay earlier levels.