This is not really a problem for open source games with an active Debian/Fedora maintainer. If there are interested packagers and you give them source code to work with, I've noticed they will be happy to build and test your package and try to keep it updated. The point of using deb/rpm is to integrate with the distro. If you want to go directly to customers and you have no intention of tying your package to the distro release cycle and working with their package maintainers, then yes, it seems it would always be a bad fit.