Here's an idea: since several Vectrex games (like Amor Attack, Bedlam, MineStorm, Star Castle, Space Wars, etc.) would also be perfectly playable with the Dingoo held normally, i.e. horizontally, wouldn't it be nice to have something like a toggle button for the D-pad controls to be rotated back 90? counterclockwise? That way, these games could be played a lot more comfortably without having to flip the whole Dingoo vertically everytime. The shoulder buttons might be perfect for toggling the controls, I would say.
Now, I don't know, if nzeemin
is still active around here anymore. If not, is there possibly another good soul capable of coding, that might be willing to have a look at the source code? It's still available online: https://code.google.com/archive/p/nzeemin-opensrc/source/default/source?page=6