As an obligatory thing, tried Doom 
The flatpak ChocolateDoom to be precise.
Graphics and game work great. Controls… swipes simultaneously move and shoot, which is bad for ammo. The default/US layout of touchkeyboard maps s forwards, v and u to turn and x back. Some other keys on other layouts do other stuff. An added difficulty level, “insanity” 
Somewhat of a milestone, playable although not perfect. Maybe we need a gaming layout for Sqeek?