POPULATION SPLIT

Privacy, in plain language.

You can play without creating an account. Daily and free-play progress stay in your browser. Friend challenges use a shared database.

Last updated: 17 October 2026.

Scores and progress

We use your browser’s local storage to save daily progress, completed scores and your streak. We keep up to 90 daily progress records and your last 200 completed games. Daily and free-play records stay on your device. When you create a friend challenge from an existing game, its saved guesses are sent to the shared challenge database so your result can be compared. You can remove it using “Clear my saved progress” in Your stats or by clearing this site’s browser storage.

Friend challenges

Creating or joining a shared challenge sends your chosen nickname, room identifier, map selection, saved lines and calculated scores to Cloudflare D1. Anyone with the invitation link can see the nicknames, progress and final standings. Your individual guesses are available only to your player session. Choose a nickname that does not identify you if you prefer.

Rooms expire 24 hours after creation and become inaccessible. Expired room and player records are deleted during subsequent challenge API requests; if no one visits, physical deletion waits until the next request. Short-lived hashed network identifiers limit excessive room creation and joining. We store a private player token in your browser to let you resume; it is not included in invitation links and only its hash is stored in the database. Clearing local storage removes this access but does not immediately delete the shared room.

Older seed-based links still work and may include the puzzle seed, mode, starting place and a score in the URL. They do not create a shared room. We do not collect audio, profile photos or friend lists.

Website delivery

Our hosting provider processes standard request information, such as IP address, user agent and requested URL, to deliver and protect the site. The game does not currently add advertising or analytics scripts, tracking cookies, or external map tiles. Fonts and game assets are served with the site.

Contact messages

If you submit the contact form, your name, email address and message are sent through FormSubmit to the site operator so we can answer. Avoid including sensitive information. FormSubmit may process information according to its own privacy policy.

Questions or deletion requests

Use the contact form for privacy questions or to ask us to delete a contact message. For scores saved on your device, use the in-game clearing option. For a shared challenge request, include the room link and your nickname so we can identify the relevant records.