Does the game have to be a platformer? In your Jam rules you mentioned making the platforming interesting so does it h a v e to be a platformer? I thought it pretty unclear.
"The game should be entirely focused on creating interesting/fun platforming mechanics. "
The term "platformer" is fairly loosely defined. Since the concept involves making a game focused around movement mechanics, something platformer-esque is encouraged and probably most pratical, but given the nature of jams (encouraging innovation) you don't have to strongly stick to the genre so long as movement is still the focus.