Medusa

Medusa, designed by Wally Welch and manufactured by Bally in September 1981, is a solid-state (SS) pinball machine notable for its "Time Locked Zipper Flippers" on the upper playfield — the last Bally game to use this distinctive zipper-flipper mechanism, where the flippers close together temporarily during gameplay. Only 3,250 units were produced.

Medusa's playfield is built around a mythological theme, featuring Medusa as the central character (artwork by Kevin O'Connor). The game features four pop bumpers, two slingshots, seven star rollovers, six standup targets, four rollunders, a 7-bank drop target, a 4-bank drop target, and a kick-out hole. Players can also use a player-controlled rubbered post between the flippers to hit the ball back into play, a feature also found on Bally's 1981 'Fireball II.'

The game's design is noteworthy for its digital displays in the playfield and red translucent lower flippers lit from underneath. A row of red lights along the top of the playfield illuminates to reflect bonus adding and subtracting. Interestingly, the backglass shown in the original flyer depicted a more revealing image of Medusa than what appeared on production games, after Bally's marketing team asked artist Kevin O'Connor to tone down the artwork.