Man, this was fun playing on stream. Like I said, your overall game design is always spot on. Definitely one of the styles on my inspiration list. (Ugh...Riri!)
The MOBA style controls made sense to me because of Dota/League. But I could see those being trickier for some players. Especially doing both movement AND attack direction using the mouse. Maybe the possibility of an auto-lock on the enemy? Remove at least the aiming mechanic from the mouse controls? Unsure if it would work. Just spitballing ideas.
I've gone back and played through. Managed to down 3 bosses so far. I can't wait to see what you do with this one. This is super fun. Great job!