I commonly search for event approaches which are unique and out of the box. I learned that Youtube is usually a good source for these ideas. All you need to do is check out Youtube and perform a search for "birthday party suggestions" and you will see several hours worth of videos with many different very good ideas. The trouble is, who has time to watch them all? So I am on a continuous quest to put together some notes to save me and perhaps other people some time.
Here is an awesome video with some crazy party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
Hope you see a number of good ideas for your upcoming event on Youtube!