Thank you for enjoying the game! I will say, you are 100% able to "orb-walk" the boss rather than just trade damage. The E also has i-frames while you're in the air, though I understand this is not directly conveyed. Tooltips were planned but I just never got around to it.
I agree, SFX would have been a huge boon. Their absence was a result of the team size restriction.
Thank you again for playing our game and for your feedback!