Light Up

About Light Up

Light Up is a logic puzzle, also known as Akari, where you light up a grid with bulbs. Place bulbs in the white squares so every white square is lit. Each bulb shines along its row and column until a black wall blocks the beam, and no bulb may shine on another. Numbered walls tell you exactly how many bulbs touch them on their four sides. Lit squares glow yellow, and clashing bulbs or unsatisfied numbers turn red, so you can spot mistakes quickly. Tap to place a bulb, switch to Mark mode to dot squares that can't hold one, and undo whenever you need. Choose 7x7, 10x10 or 14x14 grids at easy, tricky or hard levels. Each puzzle has a unique solution, and your game is saved on this device.

Game by Simon Tatham, used under the MIT license.

How to play

Tap a white square to place or remove a bulb. Mark mode (or long-press) puts a dot where no bulb can go. Mouse: left-click for a bulb, right-click for a dot. Ctrl+Z to undo.