Same idea as 2048, but on a smaller 3x3 board — faster rounds, quicker to master.
Number Merge is a sliding tile puzzle. Every move shifts all tiles in one direction, and two tiles of equal value that collide combine into one of double the value. A new tile appears after each move, so the board fills steadily and the game ends when no move can change anything. The appeal is that the rules take ten seconds to learn while playing well takes considerably longer.
Two ideas separate a short game from a long one. The first is corner anchoring: pick one corner, keep your largest tile there, and never make the move that would pull it away. Most losses come from a stray move that shifts the big tile into the middle, after which the board fragments. The second is keeping values in order along an edge, so that a row can cascade — each merge immediately enabling the next. Beyond that, it is a matter of avoiding the move that fills your last free square, since a full board with no equal neighbours is the only way the game actually ends.
Keep your largest tile in one corner and build a descending row along that edge. Avoid the move that would shift the largest tile out of its corner, since a fragmented board is what usually ends a game early.
When the board is full and no two adjacent tiles have the same value, so no move can change anything. Keeping at least one free square and some equal neighbours available is what keeps a game alive.
In principle you can keep doubling as long as you have space and moves, so there is no fixed ceiling. In practice the board size limits how far most games get, and each doubling is roughly twice as hard as the last.
Any best score is kept locally in your browser on that device, so it persists between visits unless you clear your browser data. Nothing is sent to a server and no account is needed.