Really cool idea! I read your devlog on the graphics change and think that's a great idea (not that what you currently have is bad, but I do agree your changes will fit your game better). My only complaint is the one hit gongs show everything a little quickly and I had to restart to find stuff again b/c I didn't quite have enough time to memorize it (specifically on level 3 is what I'm thinking of).
I'll definitely check back to see the changes you make! :D