itch.io

Yes ~ If you want to keep your save file safe and outside of the browser cache (which can erase save data, on occasion), you need to 'export' all save data from the extras menu. From there, using the 'import' option, you can load that save file.

I'm planning to add a new save option that lets you link the game to a local save file, so your progress is automatically stored there instead. With this option, the only thing saved in your browser will be the link, so if that's lost due to your browser cache clearing, you can just import the save file to get everything back.

My savegames survived all updates so far - playing on firefox
Had a backup but never needed it.
I use exporting to keeep the ingame list short.