Hi Sarah!
Welcome back to the Disney Parks Moms Panel. I am so glad to hear that you will be attending
Mickey's Not-So-Scary Halloween Party in October, you are going to have a "SPOOKTACULAR" time! The party itself starts at 7:00pm, however Cast Members will allow guests into Magic Kingdom as early as 4:00pm.
You are absolutely right, there is Trick or Treating. Children of all ages are able to collect candy throughout the theme park and see their favourite characters dressed in their halloween costumes! During the party, several villains will make appearances, along with other hard to find characters, including some princes! There are fireworks, which are themed and much more elaborate than what guests will see during Wishes Nighttime Spectacular. There is also the "Boo To You Parade", lead by the headless horseman!
Another perk for Mickey's Not-So-Scary Halloween Party is that tickets are limited. I have found that during events like this, the wait times are much shorter and crowds are smaller as well.
Mickey's Not-So-Scary Halloween Party is a spectacular event that you and your family will remember for years to come, I am absolutely positive it will be one of the many highlights of your stay at Walt Disney World Resort.
I hope you have a great time at Walt Disney World Resort this October Sarah. Please let me know if you have any other questions, I would be happy to make your "Disney Time" even more magical!
Stephanie