I liked your idea a lot and, at least so far, it's been one of the more creative ones. Took me back to blockorz on coolmath lol. 

I think it's fun but the enemies are slow and there wasn't much threat that they posed outside of their number. Maybe if there were some special enemies that went faster, made you slower, or maybe ate up some of the board until you've killed them would expand the idea even farther. Good job! 

I've seen a lot of submissions with the idea of matching the sides of the dice with numbers on the playing field, but I think you've done a good job expanding on this idea, by making them enemies that move around. Because you can still somewhat take it easy, you could maybe add a timer to force the player to engage the enemy more hastly and make it a bit more exciting.