Using Steam on openSUSE Tumbleweed, Kernel 4.18, Intel GPU (i7-4810MQ).

More information is needed. What is your monitor setup, display driver, LLVM/Mesa version (if applicable), etc.
Monitor: W541 laptop display ( 15.6 in, 1920x1080 )
Display driver: i915 ( I guess)
Also
$ rpm -q llvm Mesa
llvm-6.0.1-1.1.x86_64
Mesa-18.1.5-204.2.x86_64
Fallout Shelter was on the Whitelist. Why is this labeled as "Unofficial?"
Thanks @RiderExMachina, label adjusted.
Having this issue as well. The only thing rombert and I share is the i915 driver. Otherwise running Mesa 18.3dev and llvm7 on Debian Sid.
Manjaro(Archlinux) XFCE
4.18.3-1-MANJARO x86_64
AMD FX-6100
AMD Radeon HD 7800 Series
relosution 1360x768 (monitor 18.5)
mesa 18.1.7
llvm 6.0.1
Game runs perfectly so this really maybe an intel bug related.
Most helpful comment
Thanks @RiderExMachina, label adjusted.