I borked my system and now the pinephone only boots to a blank screen. So I'll take this opportunity to reinstall retropie and record my steps as I go.
Edit: Moved the installation instructions into post #3
Notes: Emulationstation will launch games on a fresh install but fiddling with retroarch config settings seems to break it. The xmb menu driver for retroarch frontend was previously fast but unresponsive after reinstall. I was unable to get to the bottom of it so change the menu driver to rgui to avoid the headache. Select the terminal keyboard on squeekboard and the default keys for navigating the menu are capital W and X for left/right, F4 for enter, capital Z for down and the up arrow key for Up. Capital P and O are select/back keys. Disable audio-sync and video vsync settings for best emulation performance. Enable sync to content frame-rate to deal with overspeed. Select tinyalsa for audio driver to minimise stutter.
Extra: The xmb menu lag was caused by installing assets, ie the menu icons. Looks like you can disable shadows, smoothing, etc but simplest option is to uninstall the assets. Go to the configuration tool in the retropie script menu and uninstall them from there.
Edit: Moved the installation instructions into post #3
Notes: Emulationstation will launch games on a fresh install but fiddling with retroarch config settings seems to break it. The xmb menu driver for retroarch frontend was previously fast but unresponsive after reinstall. I was unable to get to the bottom of it so change the menu driver to rgui to avoid the headache. Select the terminal keyboard on squeekboard and the default keys for navigating the menu are capital W and X for left/right, F4 for enter, capital Z for down and the up arrow key for Up. Capital P and O are select/back keys. Disable audio-sync and video vsync settings for best emulation performance. Enable sync to content frame-rate to deal with overspeed. Select tinyalsa for audio driver to minimise stutter.
Extra: The xmb menu lag was caused by installing assets, ie the menu icons. Looks like you can disable shadows, smoothing, etc but simplest option is to uninstall the assets. Go to the configuration tool in the retropie script menu and uninstall them from there.