It's a nice game, I liked the idea of a reversed mario and the enemies and the mushrooms being swapped! But I don't get why you wold make the enemies bigger and make them small again... it's cool, but it should have some purpose.
If you want to get the maximum number of points, you have to collect all items and kill all enemies while they're big, but I can understand that it seems pointless at first. Thank you! :)