In Millivolt, you play as an electrical appliance repair robot named 'Robert Wattson'. You fix a microwave by entering them and solving various puzzles to put the wiring back together, replace components and avoiding obstacles. These puzzles often involve moving screws to join circuits together and activating buttons within the appliance to both traverse through the appliance and eventually fix it. Robert also faces gravity shifting in this microwave that you must traverse around whilst solving certain puzzles.