In version 0.42.7+ when publishing your game from the editor (File -> Publish menu in the editor) a code project is generated for Linux (in addition to Windows and Android) that contains a snapcraft.yaml file that can generate an app for upload to the snapcraft.io appstore as follows (all explained in your generated project’s README.md displayed on publishing your game):
-- (Ubuntu 20.04) generate a game for upload to snapcraft.io as follows:
> cd [your_published_game_dir)
> snapcraft
That’s it! Now you can upload your published game to snapcraft.io as described in your project’s generated README.md.
The editor / engine / sdk is available here:
Here’s a little example app published by the editor and available for download on the snapcraft store: