That issue at the end is such a pain because I know exactly what the cause is - and it's due to some optimizations I was originally doing with collision meshes, to target a web build.
And then at the last moment the web build fell apart and I had to pivot to windows, and that collision mesh just - never loaded. And the reset level button also broke so you can't just - restart the boss fight. Agh.
I'm glad you had fun though in spite of the rough edges - thank you for playing!