Stack Tower is a casual skill game. It requires a player to build a tower as high as possible by using non-descript geometric shapes to create new floors. The shapes slide into position from the side of the screen above the foundation and previously placed floors.
If the player stops a floor too soon before it reaches the rest of the tower or after it bypasses the previous floor on the tower, they lose the game. If they stop it too soon near the tower, the game cuts off part of the shape, and the amount of floor space shrinks.
The player must have excellent vision, hand-eye coordination and timing to stop a shape in the most precise position possible. If they experience difficulty, they can wait for the shape to slide past the tower and then slide in the opposite direction before attempting to stop and place it.
Stack Tower allows the player to open up new areas and earn double stars. The player must reach 50 points as their record number to gain access to these options. They must earn 150 stars to double the number they earn the next time they attempt to construct the tower. They can also earn 300 additional stars by watching videos.
As the tower increases in height, the colors of the floors and starry background setting change, which can make it more difficult to see when to stop a shape. The floors also slide onto the screen faster.