Sumly - Math Puzzle Game

20 hand-made magic square and polygon puzzles. No timers, no lives, no interruptions. Drag numbers until every line matches. Try the historic Lo Shu and Dürer squares.

Every line has to add up. That's the entire rule, and it's enough to keep you thinking long after you meant to put the phone down.

Sumly is a puzzle about magic polygons. Drag numbered tiles into the empty spots on a shape until every line - every side, every diagonal - reaches the same target sum. Some tiles click into place right away. Others force you to rework the whole board. No trick beyond arithmetic and patience.

WHAT'S INSIDE 20 hand-built levels, running from simple triangles to a full hexagon. Along the way you'll meet square rings, pentagons, and two puzzles borrowed from real history: the Lo Shu square, one of the oldest magic squares on record, and the square carved into Albrecht Dürer's 1514 engraving Melencolia I. Solve one and you get a short historical note about it.

HOW IT LOOKS Sumly is drawn like a technical blueprint: black ink on plan paper. Every line of the shape carries a blue dimension marker, the kind an architect uses to note a measurement, except here it tracks the running total of that line live. It turns green the moment the line is complete, and red the instant you overshoot, so you always know exactly where you stand.

A CALMER KIND OF PUZZLE There are no timers, no lives, no energy meters, and no streaks nagging you to come back. Nothing interrupts a level once it starts. Undo is unlimited, so you can rearrange freely and test an idea without any penalty for being wrong. Play for two minutes or twenty - the puzzle waits for you.

Sumly keeps a running score called your Mind Score, which starts at 1000 and only goes up as you clear levels. As it grows you move through ranks - Apprentice, Solver, Geometer, Archimedean - and you can add your score to a global Top 100 list under a nickname you choose. No account or sign-in required.

Sumly is free to play. All 20 levels and your first 3 hints are always free. If you run out of hints, you can watch a short optional video to earn one more.

SUMLY PRO Sumly Pro is a single one-time purchase. It removes ads completely and gives you unlimited hints, plus two alternate app icons (a night-blueprint blue and a green variant), and a small ◆ mark next to your name on the Top 100 list. Pro never touches your Mind Score - nobody can buy their way up the leaderboard, so every rank reflects an actual solve.

No forced sign-ups. No nagging notifications. Just a quiet board, a pencil-and-paper puzzle turned digital, and every line adding up to exactly what it should.