Onet Puzzle is a connecting-lines, tile-matching game. Across two modes (Levels and Relaxing), the player's primary goal is to clear away matching pairs of round-cornered white tiles from grass fields dotted with fences, flowers and trees.
The tiles feature pictures of a wide variety of items, including blue diamonds, cheese wedges, orange gloves, pizza slices, smiling frogs, striped umbrellas, water droplets and yellow butterflies. In Levels mode, the player attempts to beat a timer while performing matches. In Relaxing mode, they simply play at their own pace.
The player can only match adjacent tiles and those that share an edge or connect within three thin lines or two 90-degree angles. When they make selections, the tiles turn light yellow. The connect lines form only with a match. If the player can't perform one, the tiles remain yellow until they make another selection.
Onet Puzzle offers several challenges. The tiles might suddenly shift left, right, up or down after the player removes a pair. Some playfields feature small tiles in a high enough number to make seeing the pairings more difficult.
That said, the game also provides shuffle and hint boosters below the field. The player can select a button marked with semicircular arrows to rearrange the tiles into new positions. They can use a button marked with a lightbulb to highlight a pair of matching tiles with a mint green color.
The game also supplies the player with timer tiles, for example, that add more time to the timer during Levels mode. They can only use these tiles if they connect the pieces. Additionally, the tiles count down, which means they must perform the match quickly. If they don't connect the tiles in time, the pieces transform into regular tiles.