Now this is a good use of the theme! When I jumped over the edge for the first time, everything clicked and I knew this was a great premise for a platformer. The art was super clean and suprisingly atmospheric too - especially the raining level.
I definitely think this could be a full game. It doesn't even really need to be dice themed, just the platforming inside a cube idea would be super interesting to explore fully.
Good luck for the future and great job on this :)