Fifteen Yandex

A 4x4 grid holds fifteen numbered tiles and one blank space. Pocket versions of this number puzzle used a small box with sliding pieces, and Fifteen Yandex follows that classic layout closely. Number 1 belongs in the top-left corner. The sequence runs left to right, then continues across the next row until 15 reaches the final spot before the empty cell. The arrangement looks manageable at first. Trouble usually shows up after the top two rows fall into place.

How to play?

Tap a tile beside the blank square to slide it over. Another numbered piece can then move into the new gap, because the board gives you only one empty slot at any moment. Place every tile in ascending order across all four rows. Fewer clicks and less time produce the best result. If the board lines up on your first successful run, record that result and try to beat it later.