If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
The aim of this game is to get 4096 with merging 2 and powers of 2.
It is originally developed by Asher Vollmer named Threes. Then, Veewo developed 1024 based on same concept.
Use your arrow keys to move the numbers (2 and power of 2, from 2 to 4096). When two tiles with the same number touch, they merge into one.