Thanks for the positive feedback!
As for your notes
"E" has been my usual dash key for my games, as well as the grappling hook in Terraria (which I use as a dash).
The musicians I talked to were either taken by another project, or didn't have what I was looking for. (also my own music sucks)
I did have more spin attacks planned, such as SIlverblast having orbiting lasers, and Mikari's projectile being able to roll along the ground, but those were cut for time constraints. The icon for the charge speed increase was originally meant for these two.