Buggy to the point it’s non-playable
You can get through the easy, medium and hard levels just fine (though they do need to change the timer settings to reflect the size difference so you can get the proper star rating). But once you get to expert level 8 (there are only 10 in each f the 4 difficulties), there isn’t a solution that fits within the game’s established rules of 1) use every piece on the board, and 2) don’t leave any open pipes, and 3) light every bulb. Very frustrating to get so close to finishing the game, only to hit a wall you have no way around.
