Visible crew/equipment: When the spheres fly through the air you can see a "dot" following which is the camera.

Continuity: At the end of the movie, when Tim walks through the double doors, there is a toilet in the background which wasn't there in the previous scene. There was a table in its place earlier.

Visible crew/equipment: When they show all of the spheres hanging from the ceiling in the room near the end, you can see the matting that they used to hang the balls from in clear view of the shot.