What Is Fireboy and Watergirl?

Fireboy and Watergirl is a co-operative puzzle platformer series developed by Oslo Albet, first published by Coolmath Games. The original Forest Temple became one of the most-played two-player browser games ever made — and for good reason. Two characters with opposite elemental powers must work together through increasingly complex temple puzzles to reach the exit. Fireboy can walk through lava but is destroyed by water. Watergirl can walk through water but is destroyed by lava. Both characters die instantly in the green toxic pools. The entire game is built around this elegant elemental opposition.

How to Play Fireboy and Watergirl

Guide both characters to their matching exit doors simultaneously — Fireboy to the red door, Watergirl to the blue door. Along the way, collect all the gems scattered through each level (red gems for Fireboy, blue gems for Watergirl). Puzzles involve pressure plates, levers, crates, and mirrors that redirect light beams. Most mechanisms require both players to act at the same time — one holds a button while the other crosses a gap. You can play solo by switching between characters, but the game is vastly more fun with a real partner on the same keyboard.

Controls (Player 1 — Fireboy)

  • Arrow Keys — move and jump

Controls (Player 2 — Watergirl)

  • WAD — move and jump (W jumps, A left, D right)

Elemental Rules

Fireboy can safely walk through lava pools and fire streams. He is instantly destroyed by water puddles and green toxic slime.

Watergirl can safely walk through water channels and blue waterfalls. She is instantly destroyed by lava and green toxic slime.

Green pools kill both characters regardless of element. Avoid them at all times.

Tips for Solving Temple Puzzles

Communicate before moving. Many puzzles have narrow timing windows where one character must hold something while the other acts. Discuss the plan and move on "go" rather than improvising independently.

Look for simultaneous triggers. If you're stuck, look for two separate levers, buttons, or pressure plates on screen. Almost every stuck situation involves both players activating something at the exact same moment.

Collect gems without rushing. Gems are in awkward spots intentionally. Don't rush to the exit and then realize you missed a gem — you'd have to replay the whole room. Sweep for gems first on each new area.

Use crates as bridges. Many puzzles require pushing a crate into position to reach a higher platform. Experiment — if there's a crate in the room, it almost certainly needs to be moved somewhere specific.

The Full Series

The Fireboy and Watergirl series has five main entries — Forest Temple, Light Temple, Ice Temple, Crystal Temple, and Elements — each introducing new mechanics and trickier puzzle designs. The Forest Temple is the best starting point; the puzzles are fair and teach all the core mechanics. The Light Temple introduces mirror-based light puzzles. The Ice Temple adds slippery surfaces that change momentum. Each game builds on the last without ever feeling overwhelming.