How is game progress saved on the service?
- All of your saves are recorded on servers, even if the game is not supported.
- Many games support cloud saving (Steam Cloud). When you complete a game session, your files will be put into the cloud storage of your Steam account.
Can I add my own saves to the service?
Partially. If the game supports Steam Cloud and has files in it, you will be able to do file synchronization the first time you launch the game on the service.
Any other way to add saves is not possible.