Big Chungus ... excellent install name. I had a blast with this game and wish you'd been able to get an HTML build in so more jammers could experience it. Your in-game tutorial was really well executed and I appreciated all the little touches, like the scene that kicks off the boss battle and reinforcing the edge requirement. Though I do wish I didn't have to repeat it after every death, would rather jump right back into fighting.
I did find one bug. The right fist punched me all the way through the left wall and I had to initiate the boss fight again, but I still had the single heart damage from taking the hit. I tried to get it to happen again, but I just got knocked against the wall like normal.
I like the minimalistic art style. It's cohesive and helped keep me focused on the gameplay. Overall, great game and a fun no frills romp. Perfect jam entry. Great work, team!
Also, big love as a fellow GameMaker dev!