Nice! I played this to the end and defeated the final boss (which was my favorite part of the game -- I thought the way you structured it was creative).  I enjoyed the NES vibes here, from the chiptune to the injury-bounce to the change-up in colors of the tileset in successive rounds.  I liked that you created many different styles of enemies, too.  I was an avid coin-collector in the opening stanzas, but after a while it didn't feel like it advanced my journey, so I laid off a bit -- perhaps that's why I didn't get a full % in the final calculation (or maybe there were secret areas...).  

Some feedback that I hope is helpful:  I thought the arrow could be a bit more quickly responsive to the push of the button, as I spent a lot of time trying to hit the shoot button as soon as I pressed jump so that it would fire when I was still in the air.  I also thought "coyote time" on the platform jumps could help the feel.

Nice work!