Number Merge 10 is a timed connect-style number-based merge game with a sum-10 rule, drawing elements, and a cat theme. It challenges the player across levels to clear round-cornered teal grids in brass frames of numbered tiles by grouping numbers that equal 10 when added together. If the player performs well, it also allows them to adopt kittens inside a wooden fence on a grass yard on the home screen.
Many sum-10 games require the player to match only pairs of tiles in adjacent positions or across unblocked gaps. This game doesn't have that requirement. Instead, the player prompts it to draw a narrow or wide rectangle or square shape. With tiles in adjacent positions, the connecting shape looks almost like a straight line.
The potential combinations and number of tiles are different from many sum-10 games. Although the player can select pairs (i.e., 1+9, 2+8, 3+7, 4+6, 5+5), they can also select up to 10 tiles at a time. For example, they can draw a shape across a 2 tile, a 3 tile and a 5 tile; two 3 tiles and a 4 tile; or even all 1 tiles. A yellow 10 tile then appears on the grid and disappears after a second.
Number Merge 10 challenges the player by increasing the number of tiles per level. That said, if the remaining tiles at any given time don't equal 10, it also breaks high-numbered tiles into lower-numbered ones to make it easier for the player to complete a set. Additionally, it offers a refresh button that repositions tiles and a hint button that reveals a sum-10 group.