As according to your request
Honestly: I liked it a lot. I thought it was cute and had nice visuals with an appropriate choice of music.
Helpful: I thought the shots of the brown monster were an odd choice. They didn't seem to be part of the pink monster parts. Even if you cut to a competely different part of the story, the cuts shouldn't be noticed. I'm nit picking but do you know what I mean?
Clearly as a first submission you've got the goods to go far and make great flashes. Great job!