Coral Slab

Coral Slab is a calm, one-thumb Lights Out puzzle. Every slab is a small grid of glowing bulbs, and your only goal is to switch every one of them off.

The control is a single tap. Touch any cell and it flips between lit and dark — and so do its four orthogonal neighbours, in a plus shape. Because every tap changes five cells at once, the whole puzzle lives in the order you press them. Clear the edges and corners first and the centre falls into place.

A live counter shows how many bulbs are still lit; bring it down to zero and the whole slab goes dark. Every slab also carries a par — the fewest taps that can solve it — so there is always a cleaner line to chase once you have cracked the shape. Undo takes back a wrong tap and reset returns the slab to its start, so no move is ever fatal.

Ten slabs climb from a gentle three-by-three opener to a dense six-by-six finish, each with more cells and more taps than the last. Nothing here is decided by luck or a wallet: there is no timer, no forced ad, and nothing to buy. Every slab is built to be solvable with clear thinking alone, and your progress is saved on the device as you clear them, one grid at a time.

Coral Slab plays fully offline. No ads, no accounts, no network, no timer — just you, one thumb, and a grid of lights to switch off.

Features:
- One-thumb Lights Out puzzle — a tap flips a cell and its four neighbours
- Ten rising slabs, from a 3x3 opener to a dense 6x6 finish
- Beat the par — solve each slab in as few taps as you can
- Undo and reset any time — no tap is ever fatal
- No timers, no forced ads, no pay-to-win — pure logic
- Plays fully offline — no ads, no accounts, no network