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.

After X time, you will die.

There, I said it. The reason I say it openly is because I almost quit the game not understanding that this is supposed to happen.

Not really much of a spoiler.