Fun game. Took me a bit to realize what I was doing, because there was no explicit mention that adding a token also increments the adjacent tokens. Got through six of the levels.
As far as the scoring goes, I felt like it would have been better to have some sort of rating system rather than show the remaining health. Much more satisfying to see five star completion rather than "60/75."
I feel like a randomized mode could have been fairly easy to make, since all you'd need to do is do x iterations of adding a random # to a random square.
Music definitely got a bit repetitive, loop was a bit too short.