Hello everyone,
Since I switch from devuan 1 to 2, I experienced two kind of issues with some graphical tools and games.

The first issue affect some allegro based games in the repository, like Alex the allegator 4 and Ballz (So far, only these two were tested), trying to play result in system slowdown, 100% cpu peaks and very slow responses from the system.

The second one, results in some incorrect rendering on graphical tools, like Kolourpaint (Reference here).

Since all of these problems where not experienced in devuan 1.0, and I switched with a fresh install to 2.0 version, does someone has any kind of idea of what can cause those problems? Or has experienced the same kind of issue?
Some new version of Xserver packages or intel drivers?

My graphics card as shown from lshw and glxinfo output on rendering:

*-display
     description: VGA compatible controller
     product: Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
     vendor: Intel Corporation
     physical id: 2
     bus info: pci@0000:00:02.0
     version: 06
     width: 64 bits
     clock: 33MHz
     capabilities: msi pm vga_controller bus_master cap_list rom
     configuration: driver=i915 latency=0
     resources: irq:30 memory:f7800000-f7bfffff memory:e0000000-efffffff ioport:f000(size=64) memory:c0000-dffff

glxinfo | grep rendering
direct rendering: Yes

I experienced the issue in both Xfce and Trinity Desktop.

Edit 7/4/2019

Just for testing, I downgraded xserver-xorg-video-intel video driver from 2.99 to 2.21, and problem persist.
So I think the problem is somewhere else...

Edit 13/9/2019

I suspected that the problem was the graphical driver (intel i915), so uninstalled the xorg driver and VAAPI driver packages and test the games and apps, same problem.
The driver was still loaded, because it was provided also by the kernel too.

So, I blacklisted it, and well, now alex4 and ballz (I tried this two only so far) works smoothly and well!
Also KolourPaint doesn't not have the problem anymore.

$ dpkg -S i915
linux-image-4.9.0-9-amd64: /lib/modules/4.9.0-9-amd64/kernel/drivers/gpu/drm/i915
libgl1-mesa-dri:amd64: /usr/lib/x86_64-linux-gnu/dri/i915_dri.so
libgl1-mesa-dri:i386: /usr/lib/i386-linux-gnu/dri/i915_dri.so

To test, I reinstalled the xorg driver and playing around with Xorg configs.

$ cat /etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
BusID "PCI:0:2:0"
EndSection

This seems to fix the problem.