This game is a competent variation on "Lights Out": you must get a group of switches to the same state, but flipping one affects others. It is elegant and musical, but utterly ruined by ads: banners at the bottom of each puzzle, and autoplaying video interstitials every few puzzles that can't be skipped until five seconds after the video loads (making offline play impossible, I expect). Obnoxious, flow-destroying, and not worth dealing with; I'd gladly pay $3 or so to shut off ads forever, but I don't have that option.
You can also buy hints, or get a few free by clicking on an ad. Merely watching an ad doesn't count. This is a dangerous game you're playing, developer folks- bribery for ad clicks is considered click fraud by every major ad network.