hey! Yes.. it's my first time back in Unity in around 5 years.
I realized the issue was tying the physics to the Update method rather than fixed update. We already have a much nicer feeling update ready to release once review period is over. Full character rotation, inheriting swing velocity.. the way it should've been from the beginning. Kicking myself for not catching the Update issue but we sure had fun making it while... Getting back into the swing of things... :D
As for shift, I considered not using it for that reason on Windows, but couldn't think of a better key and hoped it would encourage people to disable sticky keys as it should be by default!! :)
Appreciate the feedback and glad you liked the art, it was entirely hand drawn and I think it came out really well.