So great. If you develop this into a larger game, one suggestion would be to have 3 optional “challenge stars” you can earn for each level.
Star 1: use the lowest number of runes possible for that level Star 2: “travel” the minimum distance possible for that level Star 3: bonus challenge (e.g. “don’t use the N rune in this level”)
(Perhaps these are only unlocked after earning all the runes in the game, or greyed out until you have the necessary runes to get the optimal number for a given star)
These would require different solutions, adding replayability for each level.