A dream-like game inspired by Escher, Monument Valley instantly made it into top 3 of my favourite games. Might be because of the impossible geometry, or because of the zen feeling you get when solving the puzzles and wandering between your ideas. Breaking the rules of the nature feels good. Experimenting with your own believes about the world feels good. Finding yourself in a blank state with minimal expectations about the physics and the mechanics of the universe feels enlightening.
If you want to remember how you felt as a child, discovering the rules of the nature for the first time, then go on.. Take a walk in the monument valley.