The 1-player version of this game is Playmatic's 1974 'Joker'. Pictured in this listing are two examples of this game that have differing colors in their playfields and backglasses. First example: On the backglass, the Joker lady is green and blue, and the male elfins are green. The playfield has a shamrock green background color. Second example: On the backglass, the Joker lady is green and orange, and the elfins are butterscotch yellow. The playfield background color is pea green. The post between the flippers may have been added after-factory. Both examples have green elfins on the playfield plastics. Their cabinet art appears to be the same. We don't know the reason for the two versions or if one was made before the other.