I adored the setting and atmosphere!
I've seen this core idea in some submissions already, but you made it feel really good, a well done balance between heaviness and responsiveness. I also appreciated the options to go back an action and to go back to a checkpoint.
As other users pointed out, walking is a bit slow, but personally I think it fits well, as the ball is (and feels) very heavy compared to the playing character, and a slower walk makes it easier to setup precise jumps and incentivizes the use of the ball for traveling longer distances.
Great work! :D