If someone gives you the zip file or you download it, you can extract it by:

The file celeste-linux.zip typically refers to the of the game Celeste

While not a user guide, there is a formal paper titled by Erik Demaine and others, which analyzes the computational complexity of the game's mechanics. Another paper, "Deleting Files in the Celeste Peer-to-Peer Storage System," discusses a distributed storage system unrelated to the video game. Everest - Celeste Mod Loader