Great game, with satisfying sound effects and controls! I loved the gameplay loop, and tying in the folklore as a thematically fitting way to tie in the powerup aspect was very creative!
It would have been nice to see the enemies also diversify over the course of the game - maybe they could bring in archers or priests to deal with the beast as it ravages the town over generations... but the gameplay loop you've already established is so good I can't pretend it really needs anything more :)
Great work!