There's nothing else like Monument Valley on the App Store, and for that reason alone you should go and buy it right now.
It's an experience that's almost breathtakingly unique, rich with ideas, and wrapped around a story of change and friendship, exploration, and heartbreak.
The eureka moments that pepper each of the ten levels are always accompanied by a warm smile, and even though you'll finish everything within an hour or so, it's an experience that lingers in the very best way.
This is a uniquely tactile game that could only work on touchscreen devices, a rallying cry for better thought-out control systems, more unique ideas, and the sort of exploratory gaming that the App Store is desperate for.
You play as Princess Ida, and navigate through an Escher-inspired world of shifting perspectives, impossible shapes, and grumpy crow people who caw at you when you get in their way.
Tapping on the world sends Ida scurrying to that position, and a variety of visual indicators tell you which parts of the current level you can manipulate.
Handles can be twisted, but if Ida is stood on the piece of scenery they move they'll retract.
Dotted pieces of architecture can be slid around, and this time the princess can be a passenger, moving her around to previously inaccessible areas.
The levels really are things of beauty. The clever relationships between positioning, perspective, and the manipulable chunks make for some great puzzling, and the shifts and changes you create with your poking and prodding are a thing to behold.
Each challenge is a multi-faceted thing, with huge open chambers and tightly packed spaces, all of them chiselled to perfection like digital sculptures.
You wouldn't be surprised to find prints of some of them hanging in galleries.
But Monument Valley isn't a game about stillness. It's in its movement that the real joy lies. It's an interactive piece of art, and your inputs are as important as those of the developer.
Your taps and swipes expose the doors that have been cunningly hidden, and your exploration unlocks the secrets that bubble just out of view throughout the whole game.
Even something as simple as moving from one set of stairs to the next, avoiding the attentions of a squawking crow, is a perfectly balanced game of dodge and sneak, with the simple controls making everything effortless.
The only real niggle is that it doesn't last long enough. You'll run through the levels in one sitting, even if you explore every nook and cranny.
But the story fits the chunk of levels you're presented with perfectly, and you don't feel cheated when the credits roll.
You just want to experience the whole thing again, for the first time.
As brief as it is, Monument Valley squashes enough into its gorgeous shell that quibbling about its length feels a little churlish.
The polish and poise that's gone into the final product speaks of a project made with the utmost of care and passion, and in an age of clones and cash grabs that's something to champion.
Monument Valley is an iOS game that can be played by anyone and, perhaps more importantly, should be played by everyone.
It's a short, revelatory slice of almost perfectly pure gaming that stands as an example of just what mobile gaming is capable of now.