I really like it. May I suggest maybe blending in the 3 photos onto to the background photo. Or if you don't like that maybe putting a border around them that way it would look more finished. I love it, and such a cute little man!!!
Good use of depth of field to set the child off from the background. I'd have used the clone stamp or healing brush to get rid of the blemishes on his face. You have three good child pictures. Thanks for sharing.