I have had similiar idea for a game for this GMTK, where you would play as a prisoner with a chainball attached to his feet. The game would start in a prison cell, where you would learn that the chain ball is made out of Vromathium steel and that it is a head of a steel humanoid whose head has been cutoff and turned into a chain ball. The humanoid then tells you that he can make himself lighter so that you can whirl it around easier and break out of your cell and fight off enemies - I love this puzzle idea much more, it has a Portal feel to it, the physics are pretty cool, it just feels amazing to throw the ball, the burden, and then see as it throws you around - I have made it to the "nooooooo" room and then played a couple more levels - deffinitely very interesting game.
My first idea was actually make you fight enemies with your ball and chain, hurling it towards enemies and having to grab it after so you were not locked to a spot, but after having made the physics for the mechanic to work I had the realization that it would be painful to chose to either move around or kill enemies and also that this was actually a really good opportunity for a puzzle game. While I don't think I have made enough "puzzle" levels I'm glad you enjoyed the mechanics showcase I have put together!