Thanks for the really generous feedback!
Definitely a lot of details we would have loved to implement if given more time, especially when it comes to polish and more visual indicators.
We agree the game's performance is a huge flaw and I tried to frenetically fix it in the final hours of the jam. Unfortunately couldn't get a solution working in time.
When it comes to the music our composer actually made multiple layers to it that would get added as played. You made me realize I accidentally left that disabled in the build. Gonna upload a quick fix for that.
Again, thanks for the in-depth review. If you want to see more you can check out my page here on itch. Some of the games there are made with other collaborators but "Turtle Tumble" (while quite different in theme) was made by mostly the same people who made this game.