ahoy. i gave OBF another runthrough this DD and i had fun with it.
my main bits of feedback affect the ability to control the MC. the main issues come mostly from perspective and camera angles. i found it very difficult to orient myself so that my punches/kicks face the enemy. this is especially difficult if the enemy is moving around, and due to the height of some (maybe all?) enemies being lower than yours. i think the main issue is that there's no lock-on or targeting system. perhaps a right click to focus on an enemy or something similar would help.
another thing that makes orienting yourself towards enemies more difficult is the camera control. while i'm sure there's some logic to follow, i couldn't make sense of the way the camera acted. one second, the camera would be quite far away, but it'll be on my shoulder after a 45 degree turn. i was already having trouble lining things up, and now i also have to deal with changing camera values. even on a low difficulty (non punching bag), i had trouble keeping the orb alive due to this.
another issue is that the orb is high up above ground. i think you should copy how other games tackle this, where the orb is groundlevel or on a small pedestal, and perhaps enemies have a windup time to their orb damaging attacks, to give the player a last chance to rescue it
i'm eager to see how you tackle these issues, especially since this is a kind of game i can't predict anything about. anything could happen by next DD, which i think is exciting. since you already have such an unusual setting, feel free to experiment with unusual mechanics as well.
keep up the good work and hope to see more next DD.