A very interesting concept -- unary encoding of numbers is not used nearly enough outside of formal cryptography. :D I also like how you progressively teach players the mechanics before using them as challenge.
Still, I think that the RPG-style battle is not the best visual representation for this kind of puzzle, since all of the gameplay ultimately takes place in the top bar on the screen, as you try to whittle away the opponent's digits. It is also currently very difficult to gauge the effect of selecting certain digits on the enemy's attack effectiveness, so it was hard for me to grasp whether I should focus on defending myself or just on simply erasing the enemy's numbers as quickly as possible -- I chose the latter and won, but I also think that the AI didn't try as hard as it could to beat me.