lol it's ok
I know its a demo but there is a lot that could be fixed.
The green guy goes quieter as the game goes on.
Mario just moves to fast and has stupid moved.
the sprites seem blury in some squares.
mabey the attack with the blade could do more dammage.
could use better pics next to the name.
i dont think the hp should go in minus numbers.
Could do with some blood at the end when u kill the opponent.
I hope this can help you and good luck.