Too much like a snapshot. There are too many distractions here, what's the main subject? - The first thing that attracts my attention is the boy and girl on the right, followed by the couple on the left, and finally the girl carrying the balloon.... Too much going on!
A nice family keepsake photo. For me, I wish one or two of the couples had their faces to the camera themselves. It would have added more interest for me had they been smiling at me, and I would have scored it higher then.
fun! in looking at this picture, the thing that immediatley jumps out at me is the guy dancing with the little girl. i would have loved to see a picture of just those two charming people having a fun dance!
Certainly a celebration, but beyond that there isn't a lot going here. The lighting isn't too bad as the highlights are well controlled, but the white balance coupled with the underexposure makes the scene too dark imho. I'd also recommend rotating a bit clockwise.
This picture doesn't have a clear subject which weakens it. A wider shot, with more people dancing, or a closer shot, isolating one couple would be a stronger choice.