I've added the ability to import/export saves as strings, which you'll be able to use backup your saves or transfer between versions of the game.
Unfortunately, in doing so, I've learned that through some combination of my ignorance + itch and/or Unity's WebGL, the new build loses track of saved games from the previous version. I apologize for any lost progress.
If you had completed the Prologue and wish to avoid needing to redo that, it is possible to start a new game that skips the Prologue. In the settings screen, if you enter the Konami code (Up Up Down Down Left Right Left Right B A Enter), you should be able to start a new game that skips the prologue. Entering the code does require the game to have focus and the mouse cursor has to be over the Window.
Again, apologies to anyone who lost save progress.