Privacy Policy
한국어1. Scope and Contact
This Privacy Policy applies to the Math Earth Defense app and its World Ranking service. For privacy questions or ranking record deletion requests, contact orakase83@gmail.com.
2. Data Stored on Your Device
The app stores settings, sound options, language, skins, stars, allies, local scores, medals, and learning statistics on your device to operate the game. This data is not automatically sent outside the device and can be deleted with the reset data feature in Settings.
3. World Ranking Data Collected and Displayed
When you submit a score to World Ranking or save a nickname, the following data is sent to and stored on the ranking server.
- A randomly generated player ID and the nickname you choose
- Score, reached level, max combo, and weekly/all-time ranking submission scope
- App version, run ID, and basic request information such as User-Agent
- Gameplay metrics used to prevent fraudulent submissions, such as play duration, spawned/cleared/missed enemies, correct/wrong answers, operation counts, UFO/boss kills, fever count, and all-clear count
- Weekly tournament reward grants and weekly No. 1 Hall of Fame records
- When a nickname is reported: the reporter and target random player IDs, reported nickname, reason, ranking scope, review status, and review timestamps
The ranking screen displays rank, nickname, score, level, and max combo to other users. Weekly No. 1 nicknames and scores remain visible in the Hall of Fame. Do not put a real name, age, school, phone number, email address, social account, or other personal information in a nickname. The server uses automated filters intended to block contact details and inappropriate language. Email addresses, phone numbers, addresses, precise location, contacts, photos, and payment information are not separate World Ranking input fields.
4. Ads and Third-Party Services
The app serves only non-personalized Google AdMob ads. Every ad request is tagged for child treatment and limited to G-rated content. Android advertising ID and interest-based advertising permissions are disabled in the app. Google AdMob and Google Play services may still process IP address, app set ID or other device identifiers, app and ad interactions, and diagnostics for contextual ad delivery, frequency capping, fraud prevention, and measurement. Google's handling of data is governed by Google's Privacy Policy and Google AdMob policies.
The World Ranking server uses Cloudflare Workers and Cloudflare D1. Cloudflare may process network request information, such as IP address, to provide and secure the service. The app's ranking database does not directly store IP addresses.
5. Purposes and Sharing
Collected data is used to save game progress, provide World Ranking, prevent fraudulent ranking submissions, review nickname reports, operate safety controls, serve ads, maintain service reliability, and respond to user inquiries. We do not sell personal information and do not share it with third parties except when required by law or necessary to provide the service.
6. Retention and Deletion
On-device data is deleted when you delete the app or reset data in Settings. Weekly rankings refresh weekly, while all-time rankings, weekly reward grants, and weekly No. 1 Hall of Fame records are retained to operate and present the service. Nickname reports are retained as needed for safety review and repeated-abuse handling. To request deletion of World Ranking records, include the World Ranking ID shown at the bottom of the in-app Privacy Policy screen or your nickname when contacting us.
7. Security
World Ranking communication is transmitted over HTTPS, and the server performs basic validation to reject clearly abnormal score submissions. However, no internet-based service can guarantee absolute security.
8. Accounts and Children
The app does not provide user account registration. Before a custom nickname is first published, a parent must review the safety rules and create an on-device 4-digit PIN; later changes require the same PIN. Only a hash of the PIN and the currently approved nickname are stored on the device. Users can report an inappropriate nickname in the app or hide it on their own device. If you contact us by email, your email address and message are used only to respond to and process your request.