Fireboy and Watergirl 4: Crystal Temple
About Fireboy and Watergirl 4: Crystal Temple
Fireboy and Watergirl 4: Crystal Temple is a free online cooperative puzzle platformer developed by Oslo Albet, the fourth installment in the long-running series. Fireboy is full of heat and energy and can't touch water, while Watergirl is cool and calm and can't stand fire — together, the mismatched pair must navigate the Crystal Temple's traps, switches, levers, and doors, each of which usually needs both characters working in sync to get past. This installment adds teleporters that swap the characters' positions, opening up new puzzle types not seen in earlier games in the series.
Fireboy and Watergirl 4: Crystal Temple runs entirely in the browser with no download or install required, and it's built for two players sharing one keyboard just as easily as for a single player controlling both characters at once. The puzzle design rewards patience and timing over reflexes, making it a relaxed but genuinely challenging co-op experience, whether you're playing side-by-side with a friend or juggling both characters solo.
Controls
| Action | Fireboy | Watergirl |
|---|---|---|
| Move Left / Right | Left / Right Arrow Keys | A / D |
| Jump | Up Arrow | W |
Solving the Crystal Temple's Puzzles
Each level of Crystal Temple is a maze of levers, switches, and elemental hazards that requires both characters to contribute. Fireboy can safely activate fire-related mechanisms and walk through flames, while Watergirl handles anything water-related, including pools that would instantly stop Fireboy in his tracks. Because neither character can survive the other's element, most puzzles are built around passing through danger in sequence, hitting switches for your partner, or using this installment's new teleporters to swap positions and reach otherwise unreachable levers.
Collecting Diamonds
Scattered through each level are three types of diamonds — white, red, and blue. Fireboy can only collect red diamonds, Watergirl can only collect blue ones, and both characters can pick up white diamonds. Grabbing red and blue diamonds isn't required to finish a level, but every white diamond is essential for unlocking the next one, and reaching them often demands a bit of extra puzzle-solving beyond the main path. Collecting every diamond you can find also improves your level rating, so it's worth backtracking for ones you missed.
Tips for Winning at Fireboy and Watergirl 4
Playing with a real partner is the smoothest way through Crystal Temple, since coordinating levers and timed doors is far easier with two people talking through the puzzle together. If you're playing solo controlling both characters, work through each puzzle slowly — figure out which lever or switch each character needs to hit before moving either one, rather than improvising on the fly. Watch for the new teleporters carefully, since misreading where they'll drop each character can send you straight into hazardous territory. And always grab the white diamonds you see, even if it means a short detour, since missing them can block your path to the next level.
How to Play Fireboy and Watergirl 4: Crystal Temple
- Choose your setup — Play with a friend on one keyboard, or control both characters solo.
- Enter the temple — Move Fireboy with the arrow keys and Watergirl with WASD.
- Read the room — Identify fire and water hazards and which character can safely cross them.
- Activate mechanisms — Hit switches and levers to open doors and pathways for your partner.
- Use teleporters — Swap the characters' positions to reach otherwise unreachable areas.
- Collect diamonds — Grab every white diamond, plus red or blue ones for a better rating.
- Reach both exits — Get Fireboy and Watergirl to their matching doors to clear the level.
Developer
Fireboy and Watergirl 4: Crystal Temple is developed by Oslo Albet, available to play for free on OnlineGames.io with no download or account required.
More Games Like This
If you love the teamwork and puzzle-solving in Crystal Temple, continue the series with Fireboy and Watergirl 5: Elements, or browse more free co-op games on OnlineGames.io.
