I have tested some (mostly) unmodified desktop games on Librem 5 Birch.
Notes: patched with a hack for hidpi support and manually edited config file to enable touchscreen interface, as it wasn't auto-enabled for some reason. Needs Mesa 19.3, which is not in PureOS yet. On this video it's seen running in Debian Unstable chroot where I haven't configured audio properly (it works fine otherwise).
Notes: hidpi scaling disabled in phoc. Needs some work to be fully touchscreen-friendly.
Notes: slight rendering artifacts can be seen sometimes. Requires Mesa 19.3 for blur behind the fields to work correctly (not seen on this video).
Notes: hidpi scaling disabled in phoc.
Notes: hidpi scaling disabled in phoc and window size manually tweaked in config file. Controling with touchscreen is hard :)
Notes: hidpi scaling disabled in phoc. Unusable on touchscreens (at least straight from the repos), seems to require some kind of pointer constraining that isn't working there - I have tested it with Bluetooth mouse too and it behaved similarly. UPDATE: I've got Hedgewars' touch screen interface from iOS & Android ports to work and it's playable now.
Notes: hidpi scaling disabled in phoc, squeekboard replaced with virtboard.
Notes: hidpi scaling disabled in phoc, squeekboard replaced with virtboard.
Notes: it's not hidpi for some reason and 30FPS cap makes some animations run in slow motion.
Notes: slight rendering artifacts can be seen sometimes.