What will happen if you beat all of the levels in fireboy and watergirl?

If you beat all the levels in Fireboy and Watergirl, you will successfully complete the game, experiencing the satisfaction of overcoming various puzzles and challenges. Often, finishing all levels unlocks a final cutscene or congratulatory message, celebrating your achievement. Additionally, you may gain access to bonus levels or a leaderboard if available, encouraging replayability and competition. Overall, it's a rewarding experience that showcases your problem-solving skills and cooperation if played with a partner.