I love this as a puzzle, but it feels a little silly that, since 0 is not allowed to be part of the solution, to have every space start at 0 instead of at 1.
Another masterpiece from nerdook. My favorite developer puts out another hall of fame game.
If I had a complaint, it would be that by the time you get overgrind, it doesn't up the difficulty enough to overcome the raw power you need to have harnessed on the way towards unlocking it.
Well, that, and the fact that I'm done now, so yet again I go back to waiting for nerdook's next game.