I love OnePiece, so the thumbnail got to me instantly! The game is cool! The sword is by far my favourite weapon. The general concept is really really great, but I think you lacked time in order to polish the game (implement some cool animations, healthbar, particles, scoreboard). I have to say I haven't yet met any other submissions with your idea.
Man, I can see how your team had a total blast making this game during the jam, your itch.io description is hilarious and I feel bad for you copy of unity :-) and the thumbnail, I really love it!