Thank you! Yeah, we realised shortly before submission that there was a bug in the shader. I've worked on a fix in a branch but didn't get it fixed in time for the deadline :(
Turning speed is an easy tweak, I think with the on screen joystick it's more responsive, that logic could probably be used for the keyboard controls as well!
edit: I updated the web build to fix the shader bug, which means it shouldn't crash now