Monument Valley
Having known the game for a long time but I never play it until recently. What a briliant game! I'm looking forward to Monument Valley 3.
The game idea is based on impossible geometry and optical illusion. The graphic is beautiful. And those two things result in a superb indie game.
The puzzles and storyline are relatively simple. It's not necessary a bad thing for this kind of game.
Some of my favorite screenshots from the game.