Hi Johannes, Thanks for your report.
I have packaged a new version of gemrb. For now it is available at http://mentors.debian.net/package/gemrb, and I am waiting for a sponsor to have it officially available. There is now a more informative README in the package, I have fixed a few number of issues wrt configuration paths, and updated the package to upstream 0.8.1. Regarding the resolution issue, unfortunately the games and GemRB do not support higher resolutions natively. I have added information about how to proceed in the README files, but it requires third-party patches and manual installation, eventually through wine. Best, Beren Minor
