Congrats on your first jam game! For your first jam game this is pretty good!
The presentation part was ok! The graphics were totally old school, and the music track was pretty cool (I was punching the baddies to the rythm!). Controls were simple, but did what they were meant to do.
Some hints how to make this game better:
The punching animation could be more dynamic. I'd cut some frames at the start, so that the hand is extended almost instantly, and leave the wind-down as it is.
The baddies need more range. Currently you can move and punch constantly, and not get hit at all.
Right now bad guys come from a single direction. It would be better if they attacked from different sides, even if it meant the player would stop once in a while!
Btw- you used the theme and the object! Nice!
Over all- once again, congrats on your first jam, and keep up the good work!