Wow! This is very impressive! It reminds me of ‘English Country Tune’ in a good way. The concept is at once easy to grasp, yet creative, and it’s executed on (and presented) flawlessly. ( Well, the word ‘Theme’ is cut off on the ending screen with the 6x9-pips dice, at least in the online version :-p but I point that out just to show how small the only issue I found with it is.)
It does rely on awareness of the fact that dice’s opposing sides always add up to 7 (and one more than the maximum for most non 6 sided dice as well – though only 6-siders are used in game). This doesn’t seem to be indicated anywhere … fortunately, the fix for that is easy, just add it to the game-page!