Eggnut decide not to bring Backbone to Linux officially

After a successful Kickstarter campaign back in 2018, developer Eggnut released their post-noir narrative adventure Backbone in June 2021. Sadly, they've decided not to go through with the official Linux support on it.

This is a crowdfunding campaign that did very clearly have Linux down as a platform from the beginning, so it's not the best of looks. Especially to get the announcement that it's no longer planned eight months after the initial launch. What's the reasoning being given? Here's what they said in the Kickstarter announcement:

We're very sorry to announce that we won't be porting Backbone to Linux in the near future. We did our best to do it in-house, but it took immeasurable amount of time and effort, and making it work properly would require creating a dev environment to work in which we don't have the resources for because we're deep in production for our next game. We are not in the financial position to hire another party to do the porting for us. We absolutely understand the frustration these news might bring, and we're ready to offer you these solutions:

For backers, they've offered a key for any other platform or a full refund if you prefer. That is at least a lot better than some, as we've seen plenty of other projects decide not to do Linux after including it in funding and not offer anything. Still, it's a frustrating situation, especially to be told they don't have a development environment set up for it — after being in development overall for multiple years and already being supported on Windows for over half a year.

What about Steam Play Proton, can you run it there? Reports seem mixed on it, although there's not many, with the big problem being cinematics not playing.