Nice concept. I like the fact that's reversible and that it uses a small stick instead of a d-pad.
I think it would be perfect if it also had an additional switch to act as the second paddle (the Atari originals were paired on a single connector).
This would be useful for two reasons:
1 - you could play 2 players games with alternating turns
2 - A few games used the other paddle as player one (Tac-Scan, Demons to Diamonds, Street Racer, Video Olympics, Canyon Bomber, Star Wars - Jedi Arena, AStroblast).
This is not a problem on the r77, as Stella has those games in its internal database and swaps the paddle inputs for you, but on real hardware they cannot be played with that controller (unless you have one of those Y-adapters that came with the Coleco Gemini console, or you build one).
Maybe that's what is happening on your c64? If you can, try 2 player games and see if the second player respond to the Hyperkin controller.
Edited by alex_79, Fri May 17, 2019 3:00 AM.