Thanks a lot for playing and for the detailed feedback, really appreciate it!
About the stage progression yeah, that might be a bug or something unclear on my side, because if you beat the boss you should advance every time.
The game is actually an advergame for Beast in Black, inspired by their music videos One Night in Tokyo and Moonlight Rendezvous, and it features their songs too.
Glad you liked the visuals and yeah, the music kicks ass because it is Beast in Black, awesome band!
About the difficulty: it may take a couple of runs to get through, but the key is learning the stages and using the beast form at the right moment.
As for the names, I’m not sure of any official ones since the characters come from the videos—but during development I’ve been calling them Mimmo and Pina :)