Sudoku Bubbles is a logic-puzzle game based on the traditional Sudoku number-placement game. It swaps the use of numbers 1 to 9 with colored bubbles. On a classic 9x9 board hanging in an outdoor scene, the player must add the bubbles to light and dark gray cells without repeating any color on nine-cell lines in vertical columns and horizontal rows or square sub-grids.
The player starts by selecting a difficulty level on the left side of the screen. Each level provides them with a specific number of points (i.e., Easy +10, Medium +20, Hard +40, and Expert +80). The player needs these extra points to offset their mistakes. The game penalizes them with negative points for each mistake.
Once the player selects a difficulty level mode, they can change the layout or pattern by repeatedly selecting the same button. After they find a pattern that they like, they then fill in the empty cells or spaces with colored bubbles from a bubble palette to the right of the board.
Beyond subtracting points for mistakes, Sudoku Bubbles makes the process of finding and placing the correct colored bubbles difficult by using high-gloss bubbles with a shine that distracts from the colors. Additionally, some bubbles have similar color shades or underlying colors. For example, the game has both light silvery blue and dark blue bubbles and a separate silver bubble.
The player can pop an unwanted bubble with the eraser. They also receive a pencil for notations.
