This is a pretty good video revealing some of the symbols that were in the show.
Just want to add a few things. The ritual begins with her above the stadium (In the heavens) with her hair pulled back looking transgender and possibly transhuman. She sings God Bless America and adds part of the Pledge of Allegiance to the song. Remember she openly worships Satan so when she's performing the song and saying one nation under God just remember her God is Satan. After the stars behind her align to form the American flag she descends from the roof "like a falling star" to a platform with a very noticeable Pentagram to the right of the stage.
EDIT: Here's the full 13 minute halftime show for those who want to see it themselves.