Fun, but has a few problems. The difficulty does not increase. I've played to over level 2000, and it feels no harder than level 100. Also, in quite a few levels, you can light up all the lights, without using all the wires, but the level does not complete. It is quite annoying, because I have effectively won, but not the way the game intended, so it doesn't get counted. Finally, the ads are really annoying, often requiring me to click the X button 3 times.