Monument Valley is a puzzle game for iOS (and soon Android) that tasks you with helping Ida on her journey through the ruins of a colourful, geometrically impossible kingdom.
This is a beautiful game - the art style is minimalist and polygonal without being difficult to interpret and it looks as though every pixel was carefully placed, even when you're manipulating the world by rotating towers or pulling at parapets to make new paths.
And the games' sound design is great as well, subtle sound effects make the world feel tangible, and when you slide your finger to pull a platform you hear feedback in the form of gentle, relaxing musical notes.
The world is filled with optical illusions like Penrose triangles and platforms that only align from a certain angle, where the perspective of the player determines whether a path is walkable or not.
Perhaps the most impressive part of Monument Valley is that it never feels too difficult. I don't think many people will be tempted to stop and come back to it later because it's too hard, or find a particular puzzle so frustrating that they'll want to look online for a solution (although I did have to stop and think for a while on the later levels), but equally the puzzles never feel unsatisfying either.
The game only takes about 2 hours to complete (to be honest I lost track of time while playing) but still manages to tell a story – not a very complex story, and a lot is left to the imagination, but I still felt moments of joy and sadness as I helped Ida on her quest.