In the alleyway when the Power Corps first reveal themselves, as people are rappelling from the rooftops, you see members with camouflaged jackets turning away from the wall. When Marion is introduced, they turn away from the wall a second time.
The movie takes place in "New Angeles", California, however when Chief Delario goes outside of the precinct after telling the officers that they are going to take back the streets, an Ohio flag is shown flying on the flagpole.
The goof item below may give away important plot points.
Jimmy allows Abobo to drive the "Dragon Wagon," thinking he is really Billy who has possessed Abobo, but Jimmy is the one who has the medallion half with the power of the soul; Billy has the half with power of the body, so he shouldn't be able to possess anyone.