This is definitely an original and cool idea. I think this has a lot of potential as an alternate control scheme style dungeon crawler, where movement is based through this little level-building mini game.
My main gripe is that it all comes down to rather unpredictable physics. It's really hard to tell how much a certain block will actually influence the falling dice. This is further complicated by the fact that the placement of the pieces is dictated by a grid. I feel like for something that has such dynamic physics involved, it would be nice to place the objects wherever I please.
Extra bonus points for having the dice determine it's roll even if it never makes it to the floor, and especially if it lands almost perfectly diagonally! And extra evil points for making the dice always want to land on a space that will hurt you by default.
Overall, a really cool, interesting, and unique concept, that has a lot of potential I think. Well done :)