Thanks, but I'm not sure about the metroidvania part, at least as a big metroid fan. The closest I could get is Demon Crest-like due to being more arcade-y and fiddling with already complex movement would backfire.
The boss mostly checks dodge and mid-air attacks (which most players still can't do at that point). I'll be adding minor tweaks to help with that. He ramps up to match your aggression though and going for nearly uninterrupted full health bar minigun combos can be pretty fun.