I like the idea, but you end up moving a lot to try to make the faces align right, and I think the dice moves too slow. Adding the ability to move continuously by holding the direction key would be nice too. One last thing that could make the game more enjoyable: the ability to see the faces even when they're not facing the camera.
In short I think it's a good idea, well presented, but that needs a tiny bit more to be really enjoyable.