The best puzzle games take an effortlessly simple concept and then spin it out into new and intriguing ways - and Harmony is no exception. All you have to do here is rearrange the handful of tiles on each screen, turning them from a jumbled up mess into the solution you're presented with.
You swap individual tiles around by tapping on one to begin, and then tapping on another to switch them over. Certain tiles can only be moved a certain number of times though, and you must use up every last turn between the start of the challenge and the eventual solution. It's trickier than it sounds.
You wouldn't think you could build upon this very simple core gameplay very much, but you'd be surprised at how fresh - not to mention challenging - the experience remains, even after dozens of levels. This is all down to some very clever tinkering with the number of moves available on each tile, and the variety of colors which need to be switched around. This isn't just a very visually elegant game either - the chilled out soundtrack is absolutely superb too.
The game does a rather poor job of explaining its core concepts to you, and you'll likely have to get to grips with it though some trial and error. It will all click eventually, and after only a short amount of time, but a better tutorial - or even a handful of animated walkthrough solutions - would have made things much easier to grasp.
Harmony really is a lovely game that will give you a serious mental workout. The core puzzling concept feels fresh, the presentation is absolutely gorgeous, and you'll come back to play the game just to listen to the soundtrack.
Download Harmony - iOS Universal ($0.99)