I just reworked everything on top of upstream. I upstreamed a lot of stuff I did for 0.5.4-1, so the diff is very small (repo is still the same: https://salsa.debian.org/stephanlachnit-guest/lutris). I'm still searching for a sponsor, considering the lintian output and the changes compared to upstream the biggest concern is the Flaticon license. More on this topic on the debian-legal mailing list (sadly without any response): https://lists.debian.org/debian-legal/2020/01/msg00020.html
Stephan