Excellent color scheme and an interesting idea of how jumping could interact with running. You managed to make a very simplistic game surprisingly varied and appealing.
At the beginning of the game it would be beneficial to have a bigger surface to run around on. As a new player you don't know the rhythm of the running animation and it would be great to have some space to figure that out. The collider of the ninja barrel is too big in my opinion. Touching a wall barely with your foot shouldn't kill you, only touching it with your main body should. That would be what most players expect I think. Dying earlier than that feel a lil buggy.
I enjoyed it! Good job.