How do I restore a saved game in Steam?

CrossCode seems to be properly setup for Steam Cloud based on it's SteamDB page, so whatever save you got back from the Steam Cloud is the latest data it knows about.

When you close a game on Steam that is setup for Steam Cloud if Steam Cloud is enabled for that game and Steam itself it will search for the save files and attempt to synch them with the Cloud. This can be hindered by a bad connection or Steam being down for maintenance and cause the synch to fail leaving you with Cloud data that is still outdated and local-only save data that is newer. After reformatting your PC there is a chance that save data still exists, but it's very minute and depending on the amount of time you had in-game it may take more to recover it by trying to use some forensic-quality software.

To help tell which games (claim to) support Steam Cloud you can switch your client to List View mode using the controls slightly below your account name and the big picture button in the default Steam skin. Once in List View press the + at the top right of your Library List and make sure "Steam Cloud" is checked (on). This will show a column for games that support Steam Cloud where:

• A filled-in cloud symbol means Cloud is supported & enabled
• A cloud with a line through it means Cloud is supported & disabled
• No cloud means Cloud is not supported

Then for any games which do not support Steam Cloud you can try to find their game save data location by checking their page on PCGamingWiki, which is -- as it says -- a wikipedia for games including information such as what settings it supports, bugfixes, and game save & configuration data locations.

If you're comfortable with using junctions (like symbolic links) and use Windows you can try to use GameSave-Manager to help keep your game saves synched, but it doesn't know about all games & because of the junction/symbolic link usage can cause problems if you stop using it without properly deconstructing the junction/symbolic link setup.