The level of polish of this game is awesome!
I must say that it was really really difficult to play for two main reasons:
1 - the isometric view: an isometric but slightly rotated view would have helped understand if UP was left or right from the center;
2 - I can't see what's behind the dice: it's hard to remember what face it's behind and doing the math every time is annoying. I think you could have added a small dice UI on one of the corners of the screen showing every side of the dice in the current position
Side note: I've seen many of these type of submission, but yours is greatly polished! The only thing this lacks from the others is that the important number is the Dice Face Down (as you called it).
Wouldn't have it been better to depend on the Dice Face Up?
Maybe it would have been more intuitive, as its the natural way we humans use dice!
The music and the art are too good, and it's a pity these small problems don't reflect how good this game could be! I hope you will fix them after the jam finishes!!! :D