Keen

Solve a Latin-square grid while satisfying arithmetic clues inside irregular cages.

by Simon Tatham Portable Puzzle Collection (individual implementation author unverified)

Opens on www.chiark.greenend.org.uk

Collected link — not evaluated. Official game board opened in AM02 ChatGPT in-app browser. Play inputs, completion, mobile and touch not tested. Opens on the official site.. No child-suitability or successful gameplay claim.

About this game

Keen is a number-placement puzzle in which every row and column must contain each digit from one up to the board size exactly once. The grid is divided into irregular groups of cells. Each group shows an arithmetic target and an operation, so a complete solution must satisfy both the Latin-square rules and every cage calculation. Addition and multiplication cages combine all their contained digits. Subtraction and division cages contain two cells and require the indicated difference or quotient, regardless of which digit comes first. You can enter definite numbers with the keyboard and keep multiple pencil marks in squares where possibilities are still open. The official manual also offers several board sizes and difficulties, including a multiplication-only variation.

Objective

Fill every cell using numbers 1 through the board size exactly once per row/column, and satisfy all arithmetic cage targets.

Progression

Generate individual boards in sizes 3 to 9, choose a difficulty, and optionally play the multiplication-only rule variant. No numbered campaign, account progress or daily mode was verified.

Guide based on official sources; this is not a new gameplay or mobile compatibility test.

Open play page

Game languages: EN — English official UI/manual observed in 2026-11-02 research; no other language inventory verified
Last recorded check: 2026-11-03
Desktop: screen_opened
Mobile: Not checked
User ad reports: No public ad-report summary. Ads may exist.
Age rating: Not verified
AI use (optional creator information): Not documented. AI use is not required for listing.

How to play

Left-click a cell, then type a digit to set the answer. Right-click a cell, then type a digit to toggle a pencil mark.

Code license

MIT — official license source

Simon Tatham and contributors; exact per-file rights holders may differ

Applies to software code. Original game image, audio and iframe permissions remain unconfirmed. HopJelly uses an independent illustration and links to the original game.

Image credits

Original HopJelly illustration. Illustration — not actual gameplay. No original game artwork copied.

External games, ads and content may change. A review is not an age rating or safety certification.