Surprisingly, the final boss is coming together pretty quickly.
This is a two phase fight; the first phase is pretty much done outside of the sprites. Kranion will fight you mano e mano, using moves like curling into a ball (just like you!) and spinning like a tornado. He picks his attacks randomly unlike the other bosses, so you'll need to be patient to survive against him. His attacks are pretty difficult to dodge if you aren't prepared for them, but if you are, he'll go down without too much trouble...
...until he pulls a K. Rool and fakes you out by ripping through the end of level screen. His second phase (when I do the sprites for it) is a black hole with his face, that you fight with the jetpacks from Mecha Moon. Currently this phase has no attacks but I will have him use the bounce attack from phase 1, and I'd like to make him shoot some big lasers too.
I know it's an early look, but I hope you enjoy this look at the process of making a boss.