Classic Sudoku Puzzle is a logic-puzzle, number-placement game that features elements of classic Sudoku found in newspaper and travel puzzle books. The player receives access to a black-lined 9x9 grid with nine 3x3 sub-grids in Easy, Medium and Hard and Daily Challenge modes. To access games based on difficulty levels, they must go to the home screen. To access daily games, they must use the gear at the top-right corner and the calendar button.
The player must fill every empty space on the rows, columns and sub-grids of a grid with the correct order of numbers from 1 to 9, without repeating patterns within the three areas. Each grid features some pre-inserted numbers. It also has blue numbers underneath it. The player selects a space on the grid and one of these numbers to fill the space. The game often adds the same number to other correct spots on the grid, depending on several factors, such as the difficulty level.
Classic Sudoku supplies the player with helpful Undo, Erase and Notes icons. It also supplies a Hints icon. The player receives two free hints and then must watch ad videos to use more. The game also allows the player to make five mistakes with their number selections. If they make more than five, as tracked in a central location above the grid, they must restart the game or watch an ad video to continue.