Plays inside your own copy of Outer Wilds, on your device, not in a browser tab. Opens github.com in a new tab.
How to play
Have your own copy of Outer Wilds installed: the mashup plays inside it.
Download it from its release page on GitHub (it runs on Windows).
Install it as its page says. What it asks for is just below, in the list's words.
Start the game the way its page says: some mashups come with a launcher of their own.
What it asks for
Outer Wilds on Steam with its Mod Manager, an owned Minecraft Java Edition copy, Minecraft 26.3, Fabric Loader 0.19.5 or newer and the corresponding Fabric API. The creator describes testing on one Windows PC; broader compatibility is not established.