I’ve never been much of a mobile gamer but that’s probably prejudices getting in the way. When I hear about a mobile game, I immediately think of a free-to-play game of fairly low quality and nearly impossible to play without dumping a pile of money into microtransactions.
Monument Valley isn’t one of those games. You have to pay up-front but you also don’t have to pay microtransactions and the gameplay is quite good. Unlike the stereotypical mobile fare, you could actually call Monument Valley a real video game.