Lights On
The city has gone dark. Every window has a switch, and every switch also flips the windows next to it. Light each tower with as few switches as you can.
Main Street Standard wiring. Find out what a switch does.
Old Town Built before right angles were fashionable.
Crosswire Court Crossed wiring: switches reach diagonally.
Floodlight Yard Floodlight wiring: a switch reaches all eight around it.
Neon Row Signs with a plan: light exactly what the billboard shows.
7107 Plaza Four towers, four digits, every kind of wiring.
Today's tower
The Midnight Exchange, the tower for 10 November 2026, is the same for everyone and changes at midnight UTC. Nobody has lit this tower yet.
How to play
- Click a window to flip its switch. That window and its neighbours change: lit ones go dark, dark ones light up. Hover first to see what a switch will do.
- A tower is done when every window is lit. On Neon Row and the Plaza, the billboard shows which windows to light instead.
- Par is the fewest switches that can do it. One star for lighting a tower, two for doing it at par, three for par without a hint.
- Clicking a window again takes its switch back, and so does your browser's Back button.
Where this came from
This site began as a Java and Swing homework: a photo album of rectangles and ovals, moved by a small command language, with snapshots along the way. The game is that same model, played.