I'm 2 years too late but next time take a look at Recuva and co. Saved my files a few times already :) Oh and backups. Maybe even cloud sync. Annoying but very important.
We've recovered some of the files quite some time ago; there was an outdated build in a hidden folder on our roommates computer. It's not as far as the demo build…
Thought we posted an update about that somewhere.
We keep needing to spend income from sales on food; so there has been little progress due to lack of funds to pay for assets and lack of motivation as a result.
Thank you for the advice, though; it's appreciated.