During the opening sequence the crown in the robot's head is no longer rotating and the lights are not oscillating (up and down). Also, the robot does not have the "power pack" attached, the 3 holes on his side are visible.
The shadow of the large leaf next to Jimmy Hapgood is cast on the "sky" about 5 minutes in.
(at around 9 mins) The edge of the painted backdrop isn't obscured by the rocks.