The cafeteria sign is on the left hand set of doors when they go through them, but when they are walking along it is on the right side building.
This is the final time T.J. is shown with highlights in his eyes. By the next episode, which starts the next season, they are removed for unknown reasons.
While Gretchen is trying to convince Spinelli not to get on the swing, Gretchen's glasses have no temples.
After King Bob joins Spinelli's cult while T.J., Gretchen and Vince are sitting on the stairs, Vince's right eye is colored as his skin color.
While Spinelli is watching the kids coming to touch the swing, her skin color varies a few times throughout the scene.