I LOVED the audio, it was so catchy and suited the mood perfectly, especially during the boss battle. Unfortunately I couldn't figure out how to advance past there and I was a little confused about the story. It would've been cool to have more levels before that point to figure out what was going on.
The graphics were also great, I really liked the style of the characters and the colours were well-chosen. If I had one nitpick it's that sometimes during the boss battle the blue of the obstacles was the same colour as the background, which made them hard to spot.