I really like the mysterious vibe/style. The moves are fun to utilize and solving the rooms with them fun. I could see some really creative level design making this basis for a game really shine.
Backtracking requiring re-solving is a little much - since I went left of the locked door first, I ended up doing the left entry room 4 times while unlocking the left and right control panels, not counting deaths. A bug I found was pressing 1-3 again while a move was still animating still drains the energy from the extra key presses.
It is a cool boss but quite difficult! the combat mechanics need to be a little tighter IMO. Exploding him resulted in him getting me too often so I adopted just dodging for the main strategy. I think if the explode power briefly stunned him, I'd be way more likely to want to risk engaging him. The environmental pillars were not blocking his ground explosion projectile attack. Dash/Slash Hitbox seemed to kill me at times I felt I dodged, I'm going to give this boss a few more tries now, wish me luck!