itch.io

I'll explain to you how the paint attack works, that one confused me at first too (even if your other points seem odd to me). As you've seen, the boss arena has three platforms, with a painting above each of them that has red bits. From what I've observed, the paint that washes across the screen will either be blue or yellow. One of the paintings will have the red parts change to that color. You have to then stand on the corresponding platform to avoid the actual attack (though I will say that the hitboxes aren't perfect so you could avoid it anyway), and then take the opportunity to damage the boss. Hope this helps at least somewhat.