It's decent, but nothing new or interesting. The theme is rather odd in relationship to the game-play. It's like your saying that happiness is more elusive than depression, by making the happy circles harder to get, with the unhappy circles easier to hurt you. This is very obvious when you get a stop time power-up and a happy circle appearing right next to a unhappy one, which forces you to either hurt yourself trying to get it, or just wait for the power-up to end. A somewhat melancholy game.