This is a standalone game that needs to be purchased. For PC, it can be acquired through Steam (https://store.steampowered.com/app/753640/Outer_Wilds/). It is also available on consoles, it is not available on mobile. It is playable with keyboard and mouse, but it was primarily created with a game controller in mind.

At it's core, it's a game about exploration to understand what's happening. I recommend looking around and being curious to enjoy it, and avoid rushing. It's my favorite game.

To give you an estimate, I completed the base game with all secrets in about 20-30h. There's also a DLC called "Echoes of Eyes" adding a new area to explore. In total, I spent 45h to fully complete the game.

Thank you, I just bought Outer Wilders: Archeologist Edition for Nintendo Switch, which appears to be the base game plus the expansion.