Installed the image last night, started loading my ROMS manually also.
I like the concept of the naming conventions and they way the lists are pre-generated so dropping a ROM in with the correct name, they just appear.

I changed to Robospin_v4 on the main screen as I didn't like the up/down movement go left/right.

Type "emulationstation" without quotes. This should load ES (RetroPie). Go into the RetroPie config menu on the GUI. Choose RetroPie Setup > Configuration / tools > 002 autostart... choose 1 start ES at boot. Cancel back to GUI, and reboot...