That was really cool! The presentation is polished, and the breathe is a great attack and heal; the technique and timing is satisfying to pull off!
The instruction to "Press {Jump Key} during Wall Hold to Jump" was a bit odd, given that the control to Wall Jump seems to be Holding both {Jump Key} and {Opposite Direction}. It also took me a bit to get used to pressing {Down} to let go of a wall; they're sticky! There were several times when trying to wall jump resulted in my head colliding with the wall, but wall jumping was still quite fun!
The sound design on the character is great! The thumpy pitter-patter of the walk is a treat for the ears, and it compliments the soundtrack. Also, excellent choice of music!
The boss was a great iteration on the theme of the game! Although, it was easier to jump up either wall then go up the strings of platforms.
I noticed that the doubts in the boss could push me into walls. It was funny!
Great work!