Rules: two players take turns on a 15x15 board; the first to line up five stones in a row — horizontal, vertical or diagonal — wins. Vs AI: three difficulty levels, play Black (first) or White (second); 2-Player: take turns tapping the same screen with a friend. Online: create a room and share the code — the first joiner plays against you, later joiners watch. Rematch needs both to agree and swaps colors. Undo: twice per game in AI mode — takes back one stone from each side. Stats: tap the icon at the top right to see your record by mode and level. Saved only in your browser.