Regarding the music synchronization. I might also feel like it is off due to the rather weird WASD controls. I was also thinking about doing a rhythm game for quite some time, but I would rather try to write some code that analyses the music and creates the button prompts automatically, because making them match is a rather critical endeavor. :D
It is completely fine to ignore game jam games after the jam is over. Happened to all of my games so far, but as long as you learn something during the jam, which you clearly did, it is perfect. I'm glad my comment helps you.
Feel free to check out our game. Would love to get your feedback too.