Add system log to a gist and post it here. Also say in report if game worked or not. If it crashed add a log by using the command in the launcher "PROTON_LOG=1 %command%"
Add appid 17500 to title.
It's actually about to get a native version: https://www.gamingonlinux.com/articles/zombie-panic-source-is-coming-to-linux-with-the-next-version-beta-soon.12490
Thanks.
PROTON_LOG=1x1 2018-09
Ubuntu 18.04 and the lastest nvidia driver