ON/OFF, the popular puzzle game for the iPhone/iPod touch and iPad, now has 60 new levels of fun. First released in December, the game now includes 220 levels to help twist your brain.

Created by Thomas Castel, ON/OFF requires matching boxes on the screen with switches of the same color. Each game, naturally, is more difficult than the next.

ON/OFF

ON/OFF

According to Castel, the app has been downloaded over 900,000 times. To date, only 150 players have been able to complete the game.

Take a look:

ON/OFF is free, however, the additional levels require an in-app purchase of $0.99. The universal game is available in the App Store.