Privacy notice
Chain Reaction collects no personal data, transmits no personal data, and has no account
system, no login, no advertising and no cookie-based tracking. Everything the game remembers is
written to your own browser's localStorage on your own device. This page names the
one key it uses and lists every field inside it, so you can verify the whole claim yourself in
your browser's developer tools.
Last updated: August 22, 2026. This notice is written for readers in the United States and Canada. Where the game refers to a day boundary, that boundary is midnight in the America/New_York time zone.
What is stored in localStorage
One key, chainreaction.v1, holding a single JSON object. That is the complete list.
Nothing else is written, and none of it ever leaves your device.
| Field | What it holds | Example value |
|---|---|---|
tier |
The difficulty tier you last selected, so the picker opens on your choice next time. | "standard" |
sound |
Whether the synthesized impact sounds are turned on. | true |
reduceMotion |
Your explicit choice in the pause menu about reduced motion. Absent until you set it, in which case your operating system's own reduce-motion setting is used instead. | false |
p |
Progress, split by difficulty tier. For each tier, one entry per solved level holding the fewest pieces you have used on it and whether you have earned its star. | {"standard":{"1":{"best":1,"star":1}}} |
v |
A schema version number, so a future release can migrate old saves instead of discarding them. | 1 |
There is no user identifier of any kind in that object — no account, no device ID, no random visitor token. Clearing your browser's site data for this domain erases it completely and permanently, and the game will simply start over with no levels solved. There is no server-side copy to recover, because there is no server-side copy at all.
What is sent over the network
Loading the page downloads the HTML, one stylesheet, the physics engine, the level data, the game script, a service worker and a small SVG icon from this domain. Once they are cached, the game itself makes no network requests: it is a simulation running in your tab and it needs nothing from anywhere.
The page loads one first-party performance script, the Tencent Cloud RUM agent, which reports
aggregate page-load timings and JavaScript errors so the operator can tell whether the site is
working. On the first paint the page also classifies where the visit came from — search, social,
an AI assistant, or direct — from the standard document.referrer value your browser
already sends and from any utm_ parameters in the address bar, and reports that
single label alongside those timings. That label is a category, not an identity: it distinguishes
"arrived from a search engine" from "arrived from an AI assistant" and nothing more. No gameplay
data, no level progress, no piece placements and no personal data are ever included.
Cookies
Chain Reaction sets no cookies. It does not use cookies for functionality, for measurement or for anything else.
Children
The Sprout tier exists so that a young child can play without ever being punished by a fail state or a timer. Nothing about that tier — or any other — collects information from a child, or from anyone else. The game asks for no name, no age, no email address and no permissions.
Your rights
Because no personal data is collected, there is nothing to request, correct, export or delete from an operator's records. The only data that exists is on your own device, and you control it directly: clearing site data in your browser removes all of it. Residents of California, Virginia, Colorado, Connecticut and other states with comprehensive privacy laws, and residents of Canadian provinces under PIPEDA, have nothing to exercise here for the simple reason that nothing about them is held.
Changes
If a future build starts storing something new, this page and the table above will be updated in the same release. The date at the top of this notice is the build date of the version you are reading.