How do I open the zip file as an app on Linux?
In general, you need to unzip the downloaded game archive to any place you want. Then, locate the game's .x86_64 file and follow these steps:
- Right click the file
- Choose 'Properties'
- Go to the 'Permissions' tab
- Tick 'Allow executing this file as a program'
- Close the dialog
Now, you are able to run the game's .x86_64 file and play it normally.
I'm afraid, in this case you'll need to search the internet for information regarding your exact Linux distribution on how to run typical Unity games there. Maybe you need some specific commands in the terminal. This game should work normally on several versions of Ubuntu, also some people have reported it working on Manjaro and certain desktop environments that come with Debian distro. In general, it should also work on many other modern Linux distributions.