Ahoy there! I wasn't able to get your game running. On my desktop machine running Nvidia proprietary drivers, I get an error (not surprising - AFIK, kmscube isn't intended to work with them) saying:

"drmModeGetResources failed: Invalid argument
failed to initialize DRM"

On a laptop running Intel Sandybridge graphics with Mesa 18.2.2, I get a white screen when switching to a TTY and attempting to run it, which doesn't seem to respond to anything except Ctrl+C. When returning to the TTY, I see output that lists EGL and OpenGL extensions, but no indicators of problems.

I'm happy to invest a little time in getting things running, but I'd like to wrap up my impressions/feedback by tomorrow and may not be able to include KMSshooter.

amdgpu_device_initialize: amdgpu_query_info(ACCEL_WORKING) failed (-13)
amdgpu: amdgpu_device_initialize failed.
do_winsys_init: DRM version is 3.27.0 but this driver is only compatible with 2.12.0 (kernel 3.2) or later.

failed to set mode: Permission denied

This game failed to play.

amdgpu_device_initialize: amdgpu_query_info(ACCEL_WORKING) failed (-13)
amdgpu: amdgpu_device_initialize failed.
do_winsys_init: DRM version is 3.26.0 but this driver is only compatible with 2.12.0 (kernel 3.2) or later.

.....