Undermine: Four in a Row

Undermine is a tense two-player board game for one iPhone or iPad lying on the table between you.

Take turns placing chips on your own entry row or moving any chip on the board — yours or your opponent's — one step in any direction. Be the first to line up four of your colour, across, down or diagonally.

But 18 mines are hidden under the 6 × 6 board, three in every row, and nobody knows where. Whenever a chip steps on a mine, it flips to the other colour. Push your opponent's chip onto a mine and it becomes yours — or complete their line by accident and hand them the win.

• Two players face to face on one device, or VS Bot at Easy, Normal and Hard • Tabletop layout: each player reads their own end of the screen • Learn in a minute with illustrated How to Play cards and in-game tips • Undo a move by watching a short ad • Your game is saved automatically — continue any time • View the mines when the game ends and see where it turned • Free with ads; a one-time Remove Ads purchase turns them off • English and Traditional Chinese

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