I'm so sorry, but I couldn't figure out any jumping. The timing of sound effects, and the changes in UI colors didn't seem to communicate anything either. The buttons for the rock paper scissors in the top right were never able to be pushed. The font was hard to read. And the music seemed like two unrelated loops with mere seconds of content that was both grating and a little nauseating at the same time.
All that to say, the visuals look really nice. I can imagine some camera movements at the beginning of levels and lighting with shadows would look really cool.
With jams, I like to sometimes use external free resources with music and sounds if I am running short on time. What did you make your music in?
Looking back I think I should have added more feedback to inputs on the game in general. The color changes on the button correspond to when you are supposed to hit the button. When it first changes it is the person trying to jump who is supposed to hit it and then when it changes again the person being jumped is supposed to hit it if that makes sense. Kind of like a game of Rock Paper Scissors. You can push the buttons I just didn't think to add feedback to when you hit the buttons and there are keyboard inputs you can use as well if you don't want to use the on screen buttons. To answer your question though I use LMMS for music/sound effects.