AFAIK, the appimage is available for download on the official widelands web page. It works without any problems. (Well, I haven't played it for so long, but each tribe can be started without any problems.)

There's also a flatpak available.

I'm not sure, if that's a solution to your problem. Is your problem just running/playing Widelands, or running Widelands using the official Debian/Devuan package?