Privacy policy

The short version

You can play every puzzle on this site without signing up, giving an email address, or telling us anything about yourself. Your scores, saves and tutorial progress are written to your own browser's local storage. They are not uploaded anywhere, and we cannot read them.

The exceptions are ordinary web things: the server that delivers these files sees your IP address, and the advertising partner sets cookies in your browser. Both are described below.

What is stored on your device

The game uses your browser's localStorage — a small key-value store tied to this domain. Nothing in it is transmitted to us. It holds:

• Your player profiles — the names you create, so several people can share one device and keep separate scores.
• Your scores — per difficulty, with time, mistakes, hints used and the date.
• A record of your last 20 finished games — the moves you made and how many seconds into the game each one happened, so the review screen can show where the time went. Older games drop off the end of that list.
• The puzzle in progress — so a refresh does not lose your board.
• Tutorial progress — which of the nine levels you have passed.
• Your language choice — English or Chinese.

You can see all of it in your browser's developer tools, under Application → Local Storage. To delete it, clear site data for this domain; the game will start fresh on the next visit. There is no "delete my account" request to make, because there is no account.

One more value lives in sessionStorage rather than localStorage: a short message shown once after a player is created or renamed. It disappears when you close the tab.

What the server sees

Like any website, the servers that deliver these pages keep short-lived access logs. Those logs contain the IP address that requested the file, the browser's user-agent string, the page requested and a timestamp. They exist to keep the site running and to spot abuse, and they are rotated out on the host's normal schedule. We do not combine them with anything else, and we do not use them to build a profile of you.

Advertising

This site is free and is funded by advertising. Ads are served by Google AdSense.

Google and its partners use cookies to serve ads based on your prior visits to this and other websites. This is what makes an ad for a thing you already looked at appear here; it is also what pays for the puzzles. Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.

You can opt out of personalised advertising:

• Google Ads Settings — turn off personalised ads, or opt out of specific partners.
• aboutads.info — a single page covering many advertising companies at once.
• Your browser — blocking third-party cookies stops most of this, though some sites will then behave oddly.

If you are in the European Economic Area, the United Kingdom or Switzerland, a consent message appears before any advertising cookie is set, and you can change or withdraw that choice at any time from the same place. Declining does not block the puzzles — you still get the game, just with non-personalised ads.

Google's own description of what it does with data from sites that use its services is at policies.google.com/technologies/partner-sites.

Analytics

There are none. This site does not run Google Analytics, Plausible, or any other visitor-tracking script. The only third-party code on the page is the ad unit.

Your rights

Under the GDPR, the UK GDPR and similar laws you have the right to access, correct, delete, restrict or object to the processing of your personal data, and to lodge a complaint with your local supervisory authority.

For the game itself, the practical answer is short: the data is already in your browser and under your control, and clearing site data deletes it completely. We hold no copy to delete. For data collected by the advertising partner, the request goes to Google — the links above are the fastest route, and their privacy policy explains the process.

California residents: this site does not sell personal information, and has not done so in the preceding twelve months. The ad partner's own disclosures govern its processing.

Children

The site is not directed at children under 13, and we do not knowingly collect personal information from them. There are no accounts and no forms, so the only data involved is what the browser stores locally plus what the ad partner collects; if you are a parent and want the game to run without advertising cookies, the opt-out links above are the way to do it.

Changes to this policy

If what the site stores or who it shares with changes, this page changes with it, and the date at the bottom moves. Material changes — a new advertising partner, a new category of data — will be called out at the top of this page rather than quietly edited in.