It really depends on what you mean when you say "you don't want to miss out on anything at the party". If you truly want to get pictures/signatures with all the characters, see the parade and fireworks, ride some rides, trick or treat, and hit a dance party then I say YES you need to attend two parties. We went for the first time last year and were there and in a character line before the party started and all we managed to get accomplished was all but two characters (they rotate every half and hour), the parade, fireworks, villians show, and a few trick or treat spots by a character. We are going twice this year since we felt rushed, never rode a single ride despite the practically non-existent lines, and my youngest was bummed about missing the dance party. We are doing what another poster said....hitting the parade, fireworks, dance party, and rides one day not dressed up. Then hitting all the characters and trick or treating the next party dressed up. Just my 2 cents.


plus, there is just so much to do! theres the trick or treating, the villians mix n mingle, plus all of the normal attractions to ride with such SHORT lines!
i really think it is hard to have the whole experience just going to the party once but maybe thats just me!