I like your game, and I think the clones are interesting. However, they are rarely needed, and they don't seem to help you in the boss battle. Great idea, but poor execution.
The spike patterns that you have you get past seems repetitive, and I was unable to get past level 3 and 5. However, after finding the right paths, I was able to.
There wasn't that much audio, specifically music. There were only sounds for landing on the ground and throwing punches against the boss.
There were also some bugs that I found, such as:
Still Paused- If you leave a level through the pause menu and go back into one, you will remain paused. It might not seem like it, but after you hit Escape, everything goes back to normal.
Out of Bounds- I've found multiple instances where I was able to escape the world and fall out of bounds. You can super jump over the level portals, and you can also use a bunch of clones to escape the boss arena.
Overall, you did well for your first game jam game. My favorite part is the boss battle, because you can create a mess by creating a lot of clones. :)