The good: The concept is solid, the art is cute, and it was easy enough to figure out what I needed to be doing. It has potential for a good mini-game.
The criticism: Feels just a little too unfinished, the audio is too repetitive, and I didn't get the sense that the difficulty was changing (I was expecting more ghosts over time or something to indicate a greater challenge.) Maybe I didn't give it enough time (I played until I needed to collect 17 coins). Is there an end condition? Also, the text didn't show during my playthrough, so I didn't know there was a story until reading another comment.
Overall, it wasn't bad. It just needs some extra attention to make it stand out. :)