I haven't found any records that would help with understanding the problem (what and why happens) in the log, so there may be 2 main possibilities: either they are present in the log but haven't been noticed or recognized as being related to the problem or log doesn't contain them.
However, it seems worth to note that around 2 minutes and 17 seconds have passed between the moment when process has been selected in GG:
12-22 13:05:18.975 14480 14480 E AndroidService: used: ProcessInfo [cmdline=com.fungames.sniper3d, name=Sniper 3D, packageName=com.fungames.sniper3d, icon=android.graphics.drawable.BitmapDrawable@8ef34cd, pid=10179, uid=10275, isSystem=false, isGame=true, weight=0, main=true, order=0, x64=false, rss=359392, getTracer()=0, getTrace()=-1]
and the last record in the log:
12-22 13:07:35.649 20370 20370 I SoundAlivePolicyManager: isGlobalEffectSupportCurrentAudioPath, currentDeviceType : 2
This doesn't quite correspond to your description of steps that you do to reproduce the problem. Was process selection really the last action that you performed in GG that caused device to become unresponsive and to reboot after ~10 seconds?
One thing that would greatly help with analyzing recorded logcat is to specify when certain actions have been performed. For example:
11:04:32 - "Start" button in GG's start screen was pressed
11:04:38 - Process selection dialog was opened
11:04:41 - Target process was selected
11:04:55 - Device automatically initiated it's restart
Time moments don't have to be exact, since it's not easy to precisely check when something is done, but even if it's +- 5 seconds, that's still significantly better than having no such information at all.
For example, to illustrate, the log you provided is ~27 MB, but only ~2 MB from it is most likely to contain any information of interest, since other records are from before the moment of time when you initiated recording logcat in GG. And with information about when actions relevant to the problem have been performed, only, for example, ~200 kB of log records are most likely to contain any information of interest.