Undersoil is a game made by an individual developer. It has no accounts, no sign-up and never asks for your name, email address or contact details. This page explains the small amount of information the game and the services it is built on do handle, and why.
Your progress — cash, gems, tools, the finds in your bag and museum, settings — is saved on your device. Nothing here identifies you. Deleting the app deletes it, and Settings → Erase save data resets it from inside the game.
So that your progress can be recovered if the app is reinstalled or the device copy is lost, the game signs you in to Firebase anonymously: Firebase issues a random identifier for this installation and your save is stored against it. There is no account, so a save cannot be moved to a different phone. The save contains only game state (the same data as above) and no personal information. Only that installation can read or write its own save. There is no way to link a save to a person; if you delete the app, the save simply becomes unreachable, and erasing your save in Settings replaces the stored copy with the empty one the next time the game saves.
The game reports anonymous usage events to Firebase Analytics so that we can see whether people who install it keep playing and where they stop: app opens, session length, and game milestones such as finishing a dig, cleaning a find, placing a specimen, opening a shaft level, watching a rewarded ad, and purchases (the product and its price, never payment details). Firebase attaches an app-instance identifier, device model, operating system version, country derived from the network, and — where you have allowed it — the advertising identifier. We use this data only to understand and improve the game; it is not sold and is not used to identify you.
Undersoil is free because it shows ads: rewarded ads you choose to watch for a bonus, and occasional full-screen ads between activities. Ads are served by Google AdMob, which receives your device's advertising identifier, IP address (from which it infers an approximate location), device and app information, and how you interact with the ads it shows. Whether those ads are personalised depends on your choices:
Google's own policy for the data its advertising services handle is at policies.google.com/technologies/ads. Interstitial ads are never shown in your first session and never to anyone who has made a purchase.
Gem packs are bought through Apple's App Store or Google Play, which handle payment; the game never sees your card or account details. To confirm and restore purchases the game uses RevenueCat, which receives an anonymous app-user identifier and the store's purchase receipt (product, price, date, transaction id). RevenueCat's privacy policy is at revenuecat.com/privacy.
The game can schedule a local notification on your device when your museum's offline earnings are full. Nothing is sent to a server; you can turn notifications off in your device settings.
Undersoil is not directed at children under 13 (or the equivalent minimum age where you live), and the game does not knowingly collect personal information from them. If you believe a child has provided information through the game, contact us and we will remove it.
If this policy changes, the new version will be posted at this address with a new effective date. Substantive changes will also be mentioned in the game's store listing notes.