When you first boot up Monument Valley you notice a path and a gear, the gear turns an L shaped platform. When you turn this gear you think that this rotating platform couldn't possibly create a pathway for you. You turn the gear til everything lines up and..... a clear path. What seemed like an impossible optical illusion turned into a clear path for you to cross. Welcome to Monument Valley.
Monument Valley was originally a phone game but now it's been ported to PC (same with its sequel). It's a puzzle game that makes you dissect little dioramas and makes you traverse many different optical illusions so you can reach the end. The simple art style with the soft music playing in the background gives off a comforting invitation for you to play around in it's cubic sandboxes.
It's a relatively short game. Even with the whole package including all DLCs in one its still pretty short. This is fine. Again, it was originally a phone game plus every single level feels unique and distinct from one another. One level sees you try to maneuver a crow around a play area, one level will see you walk on walls and slopes, another will have you turn spiral pillars to walk on different walls, so on and so forth.
The one thing I can see as a negative is that this game was definitely built for phones first. There's nothing wrong with using a mouse to control the game yet if you originally played the game on a phone then you'll agree when I say that the game feels way better on that. Again, it's great on mouse, it's even better on touch screen though.
If you want a small puzzle game to pass the time then this is exactly the game. I haven't played the sequel yet but if I had to guess then it's probably just more of this. If that's the case then probably buying the collection that includes both would be best for a more full experience.