What a refreshing concept!! Love the art, music, gameplay!!!
My suggestion for improvement:
1) It would be nice if there's an animation or sound when the whistle is ready to be used, something that could grab player's attention to the whistle without being too distracting. (Because sometimes I wouldn't notice the whistle is ready cuz I'm too busy avoiding the hoard of dogs haha)
2) Maybe add a leaderboard? So people would try to beat each other's score. (I only managed to reach novice villain lmao)