Cella: Heyawake Puzzle

Cella is a Heyawake puzzle — the name means "divided rooms" — for players who like unhurried, honest logic.

The grid is cut into rooms, and some rooms carry a number. That number is exactly how many of the room's cells you fill. Two filled cells never touch side by side. Everything you leave empty forms one single connected area — and no straight line of empty cells may run through more than two rooms. Tap a cell to fill it; press and hold to mark it empty.

ONE SOLUTION, EVERY TIME
Every puzzle has exactly one solution, checked before it ships by a solver that only uses techniques a person can follow and explain. The hint button uses that same solver: it shows the next step the board allows, and tells you which idea it used.

LEARN IT BY PLAYING IT
Heyawake's last rule is about neither a single cell nor a single room, and no sentence in a rulebook makes it obvious. The walkthrough hands you real positions and asks for the one square that follows, then shows you why. No board in it was made up — each is a genuine puzzle stopped at the moment the idea it teaches becomes the forced next move.

THREE WAYS TO PLAY, ALL OFFLINE
• 12 campaign chapters, from gentle openings to genuine work
• A daily puzzle, the same one for every player worldwide, with a gentle Monday and a demanding Sunday
• Endless mode in four difficulties: Easy, Medium, Hard, Expert

MEASURED IN MONTHS, NOT STREAKS
Fill in every day of a calendar month and the month earns its own trophy. There is no streak to lose: a day you missed can still be filled in from the archive, so a week away from the game costs you nothing.

BUILT TO BE PLEASANT
• Warm Material 3 design, light and dark, following your system colours
• Completely offline — no account, no sign-in, no network needed
• Boards shaped for a phone held in one hand
• No countdowns you did not ask for and no interruptions

27 languages supported. No account required. Pure logic.