Cool game! I enjoyed playing it a lot. I thought it was pretty challenging, but not in a bad way. Being able to just slide a die over from a few spots away also was quite satisfying, in contrast to the more classic bejeweled way of doing things. I haven't played match 3 games in ages, so that's still my reference :)
The black die reroll button was a nice 'oh damn, save me please' button with a little risk attached to it. Fun!