Heck yeah, mini master hand. Dude, boss battles like this are HARD to tune and get right, but I feel like you pulled it off. You left a good amount of time to give us opportunities to strike and learn his habits. The sprite animations were pretty slick. Well tuned strike combos, and sometimes you really have to time the jump perfectly to hit him.
At some point the hand disappeared for me-- seemed like that might've just been the end, but I thought I'd mention it in case that wasn't supposed to happen XD
I like that you have to literally get out of the hand in the beginning-- clever!