One Line Puzzle is a maze logic-puzzle game with a drawing element. It's broken into four modes that feature fifty puzzles per mode. The player's goal is to draw a line across empty spaces and between blue-gray diamond-sided square studs. Unlike many similar games, the player can choose any puzzle to play without restrictions.
The line drawn by the player is a colored band with a dashed white line down the middle. It makes the line look like a road on a landscape. When the player successfully covers every empty space with this road, the blue-gray studs spin in place.
One Line Puzzle offers the player an option to turn the lights off to make the challenge a bit more difficult. The grid and spaces turn dark blue, and the studs stand out with dark gray coloration.
The game also helps the player initially in several ways. It displays a white glove to show them how to draw a path. It offers a hint button marked with a magnifier glass that draws part of the path for them. The player can use this tool 20 times. If they become stuck at any time, the game also provides them with a semicircular arrow button to reload the grid.
