You are correct, it does not launch on Ubuntu 18.04 as the glibc version on your system is very likely 2.27. I've now compiled against an earlier version and confirmed it to run successfully on a brand new 18.04.4 VM. The updated file is now available on itch.
For the windows version, make sure to unpack the whole zip file before attempting to launch, and ensure that the working directory is the same as the folder which contains the resources folder and the app itself. Directly double clicking the unpacked exe should do the right thing, though.