Undercell — Support
Last updated: October 19, 2026
Undercell is a pentomino logic puzzle for Android and web browsers. Pentominoes lie hidden under the board; sensors point toward the nearest one. Work out where the shapes are, then open them — opening an empty cell ends the round.
Contact
support@upside.com.pl. Written requests are answered within two business days. If you are reporting a problem with a specific board, include its share code — that is enough to reproduce it exactly.
Where to play
The game runs in your browser at upside.com.pl/undercell/play, and on Android from Google Play. Both are the same game and both work offline.
Board codes
- A share code looks like UNDER-TEMSRGS-0P1. It names a board's starting state and nothing else, so whoever you send it to meets that board exactly as cold as you did.
- To open one, tap the menu, then Play a code. You can paste the whole message it arrived in — the game finds the code inside it.
- A code that is refused has a typo. Every code carries a check character for exactly this reason: the game would rather tell you the code is wrong than quietly open a different board.
Saved boards and progress
- Your settings, progress and kept boards are stored on your device only. There is no cloud sync. The only data that reaches us is what you choose to post to a leaderboard (see below).
- Uninstalling the game, or clearing its data, erases your settings, your progress and your kept boards permanently. In a browser, clearing the site data does the same. They cannot be recovered.
- Moving to a new device does not carry your progress across. Share codes do travel, so a board you want to keep can be sent to yourself.
Leaderboard
- Each board can have a public leaderboard. It is optional: nothing is posted until you choose Post my time or switch on Post my times in Profile, and the game works fully offline without it. After that, every board you solve is posted, including runs with hints, until you switch Post my times off. Runs solved while you are offline are posted when you are back online.
- On Android you post with your Google Play Games account. If Google Play Games is not available on your device, you post as a guest under a generated name, and that guest account lives in the app's storage: clearing the app's data loses it. Android backup may copy that storage, including the secret access token, to your Google account backup and restore it when you reinstall the game. In a browser you also post as a guest under a generated name, and the game keeps a secret access token in the browser's site data; clearing the site data loses access to that guest account. Accounts on different devices and platforms are separate.
- Posting stores your display name, your time and a replay of your moves on our server, and shows them to anyone. Details are in the privacy policy, and the rules are in the Undercell terms.
- To delete your leaderboard account and its data, see how to delete your account.
Purchases
There are none. Undercell is free, has no in-app purchases and shows no advertising, so there is nothing to restore or refund.
- Legal name
- UPSIDE Dariusz Majewski
- Address
- Świętej Jadwigi Śląskiej 27, 43-300 Bielsko-Biała, Poland
- VAT ID
- PL 5471980532
- support@upside.com.pl