What is Blueberry?
Blueberry is a 9×9 grid puzzle divided into irregular regions by thick borders. A number beside each row, above each column, and in the corner of each region shows how many cells to fill there. The interface has a gray grid with a dot in the center of each cell, the current date below the title, and Reset, Undo, Redo, and Check buttons at the bottom.
How to play Blueberry
Read the clues first: numbers on the left give the row totals, numbers at the top give the column totals, and the small numbers in the region corners give the totals for those irregular areas. Click cells to mark them. Use Undo or Redo to correct a mistake, or Reset to start over. When the grid is complete, press Check to verify your solution.
Every cell belongs to a row, a column, and a region. The irregular region shapes make the puzzle less predictable than a standard square grid. The interface uses only numbers and thick borders, with no color or animation, so the logical structure stays in focus. A timer records the solving time.
What the browser retains
The Check button verifies the grid. The browser stores the state of every cell, the full Undo and Redo history, elapsed time to the millisecond, and an indicator for each clue showing whether it has been used. This information survives a page reload.
Modes
Daily is the default tab and shows the current date beneath the title.
Grids 1, 2, and 3 are three numbered buttons beside the tabs. Grid 1 is selected when the page opens.
Plus is a tab between Daily and the grid selector. It is currently grayed out.
Tips for solving
The sums of the row clues, column clues, and region clues must match. Calculate the total before placing the first mark and use it as a checkpoint if you get stuck.
Regions marked with zero are good places to start. Clear them completely to constrain the rows and columns that pass through them.
The timer starts when the page loads, not when you make the first click. If time matters, read the clues before opening the tab.
Common questions
What is the size of the grid?
It is a nine-by-nine grid divided into freeform regions. Each row, column, and region has its own clue.
Can you go back?
Yes. Reset, Undo, and Redo are below the grid. The game preserves the move history in the browser, even after a page reload.