As Raspberry 4 is delivering form China, I turned legacy little gadget into retro gamebox just for fun. It could not too complex, but there were some trial errors as always.
SENS Game controllers
16GB+ Micro SD Card
Most of setting can be left unchanged, but there might be some madatory changes required depending on environment.
setting:configuration->raspi-config->1.change user password
(need to make sure that the password for WiFi can not have a special character @)
setting:configuration->raspi-config->5.interfacing option->enable ssh
After rebooting, then install the lightdm for autologin
$sudo apt-get install lightdm
setting: configuration->raspi-config->3.boot options->4.desktop autologin
If HDMI interface is default for sound, there is no issue but when using 3.5mm analogue audio out, it requires additional configuration changes.
To get audio through the 3.5 jack: Retropie configuration > Audio > select option 2 (headphones – 3.5mm jack) > OK > restart system
for un-archiving Rom packages;
$apt-get install unrar-free p7zip