UH999 game

UH999 game is a vertical number sliding block mobile game. When you swipe, all tiles move in the same direction, and two tiles with the same number merge into their sum when they collide. Each time a 2048 tile is merged, one point is scored. After each move, a new number tile appears on the board; as the score rises, larger numbers are also added. The round ends when the grid is full and no adjacent numbers can be merged anymore. Hint marks a relatively favorable swipe direction, and Undo returns to the previous step. You need to keep large numbers stable while leaving space for newly appearing tiles, and cannot focus only on merging the pair right in front of you.