Meltdown

About Meltdown – Daily Reactor Logic Puzzle

Meltdown puts you in charge of a reactor whose edges connect to each other. Sixteen cores form a four-by-four grid. Each pulse flips the chosen core and its four immediate neighbors, turning glowing cells off and dark cells on. A pulse on the left reaches the right edge too, while a pulse on the top reaches the bottom. The challenge is to see the whole connected board instead of treating its corners as safe places.

Every daily reactor has a five-pulse shutdown, with an eight-pulse budget for your committed sequence. Experiment without a timer, undo your last move, or reset the board as often as you like. Hover over a switch or focus it with the keyboard to preview its reach. Once every core is dark, commit the shutdown to record your result. Fewer pulses earn a higher score, and five is perfect.

Everyone gets the same daily reactor. Boards cycle through all 4,368 five-switch combinations before repeating. Your finished shutdown joins the platform's daily progress, statistics and leaderboard, while your share celebrates the pulse count without revealing the switch sequence.

How to play Meltdown

Turn every reactor cell off in eight pulses or fewer.

1. Tap a cell to flip it and its four neighbors. Lit cells turn off; dark cells turn on.
2. Blasts wrap across edges: the left edge touches the right, and the top touches the bottom.
3. Experiment freely. Undo or reset your sequence at any time before committing.
4. When all cells are dark, commit your shutdown. Every reactor can be solved in five pulses.