Party on 27th Floor With Balloons & Pigheads

by Galiphba
(Amarillo, Texas, USA)

This will be an easy one. I forgot the name of this 2000's movie that starts out with a party on the top floor of a building, and then certain guests get e-mails to go to the 27th floor following smiley face balloons.

When they get there, children's music is playing on a record player and a child's party is set up. Everyone has a placecard describing their true nature of who they are.

One of the guests is supposed to be a world famous chef and the others are just an odd assortment of nobodies.

The rest of the movie, they go on a scavenger hunt and get killed off one by one. The killer likes to use pigheads and references pigs and nursery rhymes.

What is this movie? Thanks!