If you played the Downloadable version of the Demo, you’re good to go! Same save files.
If you played the browser version, then no, unfortunately. I have been unable to work out how to extract browser saves.
I have added a button that lets you skip straight to Week 4 if you want, so you can get straight into the new part of the story, BUT it won’t know your days 1 through 21 gold score, so you would have to play those days again to unlock some Sandbox potions.