wire used0 / 40
lamps lit0 / 3
efficiency—
Drag from any wired cell to lay copper. Reach all lamps with wire to spare.
Workbench
A lamp needs a continuous copper path from the battery's positive terminal. Every crossed cell loses a little voltage — dim lamps mean long routes. Obstacles (dark slate cells) are impassable. Efficiency = shortest possible route ÷ your route.