I think jumping doesn't work at all, or uses a button that isn't on the keyboard. In any way, I think this is quite a weak interpretation of the theme. There's no point in trying to beat other levels than level 6 since it won't reward you in any way whatsoever (or maybe it does - if I could jump I would know!) So, players would probably restart the game until they rolled a 6 - that's not very fun.
Viewing post in Roll The Dice jam comments
Hey, don't beat yourself about it, everyone begins somewhere. My first games were also terrible. Sorry if I phrased my feedback too negatively - it was just meant to be constructive criticism, just things to keep in mind the next time you make a game. It's not your fault you don't have experience!
...but yeah, jumping doesn't work.