I like the art you used for your title. While simple maybe next time have it where there a button for left punch and right one. Just while simple just I feel maybe a very small variety would have helped like another button for other side punch. Also maybe have it where their boxing gloves didn't have that middle dot on them, maybe just have it where it remove or make it two as it look kinda odd. Just wanted to share my personal feedback. Nice boxing game you have here. :)
Also one thing, the gamepage, if i may suggest maybe not have the boxers on both side, just that with the middle image just made it intense when view.