I had an influx of crunch yesterday, and had to start over on my game!!! I have 7 hours left, but please, please, please! Can someone give me a tip for making a funny 2D platfromer?!
Since this is a jam where you have expand upon the game, you should envision the game, and ONLY implement the main mechanic, so for the platformer, think of what you want to make it special, and only implement that along with the basics. This is just my advice, and what I did to submit a game even though I had no time. Hope this helps :)