Now, having Arduventure publicly available here Arduventure - 12th TEAM a.r.g. game it is easy to see how the uploader works with that special mode the game uses:
https://photos.app.goo.gl/VhTDN1eoOyYkoH5E3
Turns out that loading a new game or restoring Arduventure is a breeze
Summarizing:
To install a new game over Arduventure
- Install https://github.com/eried/ArduboyUploader/releases/latest
- Browse a new game here: http://arduboy.ried.cl and click “Upload to my Arduboy” button
- Connect your Arduboy with Arduventure, select Upload from the main menu and press UP*
*Normal games do not require to select anything and/or press anything
And, if you need to restore Arduventure:
Restore Arduventure
- Install https://github.com/eried/ArduboyUploader/releases/latest
- Download the Arduboy file from http://www.team-arg.com/ardu-downloads.html
- Double click the Arduboy file