About Pixel Logic
Pixel Logic is our take on the nonogram, a picture puzzle also sold under names like picross and griddlers. You get an empty grid with numbers next to every row and above every column. Each number is the length of a run of filled cells in that line, in order. Work out which cells are filled, and a small piece of pixel art appears.
Our version has 32 original pictures that we drew by hand: 11 at 5x5, 13 at 10x10 and 8 at 15x15. They include a heart, a ghost, a penguin, a hot-air balloon, a castle, a lighthouse and a whale. While you solve, the grid is plain black and white. When you finish, the picture fades into full color from one corner to the other and its name is revealed.
Every picture has been checked by a line solver, a program that only uses the kind of reasoning you do: look at one row or column, work out which cells must be filled or empty, and repeat. Each puzzle is completed by that process alone. That means two things for you:
- The answer is unique. There’s never a spot where two different pictures both fit the clues.
- You never need to guess. Some line always has a cell you can prove.
Several of our first drawings failed this check. The cat’s ears, the anchor’s arms and the whale’s waves all left pairs of cells that could be swapped without breaking any clue. We redrew each of them until the solver could finish them.
How to play
- Pick a size from the tabs at the top of the menu, then pick a puzzle. Solved puzzles show their finished picture and your best time. Started ones show your progress.
- Fill cells. With the square tool selected, tap a cell to fill it. Tap a filled cell to clear it.
- Mark empty cells. Switch to the X tool, or right-click with a mouse, to put a cross in a cell you know is empty. Crosses are just notes for you. They never count against you.
- Drag to paint. Press on a cell and drag. The stroke locks to the row or column you start moving along, so you can fill a run of eight cells in one smooth swipe without clipping the line next to it. The first cell decides what the stroke does. Start on an empty cell and you fill (or cross) empty cells. Start on a filled cell and you erase filled cells.
- Auto-cross. As soon as a row or column’s filled cells match its clue exactly, the clue dims and the rest of that line is crossed out in light gray automatically. If you later change the line so it no longer matches, those automatic crosses disappear again.
- Progress. The Done percentage counts how many rows and columns currently match their clues.
- Undo and Clear. Undo reverses a whole stroke at a time. Clear wipes the board after a confirmation.
Like a puzzle printed on paper, the game won’t tell you when a filled cell is wrong. The picture only completes when every row and every column matches its clue. Your progress on each picture saves automatically, and a hidden tab pauses the timer.
Strategy tips
Start with the big numbers
In a 10-wide row, a clue of 8 has to cover the middle six cells no matter where it slides. Push the block as far left as it will go, then as far right. Any cell covered in both positions is filled. This “overlap” trick opens almost every puzzle.
Add the clues up
For a line with several clues, add the numbers plus one gap between each pair. If a 10-cell row has clues 3 4 2, that’s 3 + 4 + 2 + 2 gaps = 11. That doesn’t fit, which means you’ve misread a clue. Now try 3 3 2: 3 + 3 + 2 + 2 = 10, so the whole row is fixed. When the total equals the row width, you can fill it in one drag.
Zeros and full lines first
A clue of 0 means the whole line is empty, and our game crosses it out for you. A clue equal to the grid size means the whole line is filled. Knock these out before anything else.
Work from the edges
A filled cell touching the border pins the first clue of that line against the edge. If the first clue in a row is 3 and the leftmost cell is filled, the first three cells are filled and the fourth is empty.
Cross out freely
Crosses matter as much as fills. When a line’s clue is satisfied, the auto-cross does the job for you. For partly solved lines, mark cells that no clue can reach. Those crosses often split a line into short segments where only one clue fits.
Alternate rows and columns
Every cell you prove in a row is new information for a column. When you get stuck, sweep across all the columns you haven’t touched since your last change. On 15x15 puzzles, that back-and-forth is most of the game.
Want a slower walkthrough? Our guide How to solve nonograms solves a small puzzle one line at a time.
FAQ
Is every puzzle solvable without guessing?
Yes. We ran every picture through a line solver before shipping it. If one line of reasoning at a time wasn’t enough to finish the grid, we changed the drawing.
Why don’t wrong cells turn red?
We wanted the game to feel like the paper version, where the clues are the only feedback. If a row won’t close, check it against its clue. The auto-cross only appears when a line matches exactly, which is a strong sign you’re on track.
Can I replay a picture I’ve already solved?
Yes. Open it from the menu, or use Play again on the win screen. Your best time for each picture is kept.
How do I play with a keyboard?
Use the arrow keys to move the pink cursor. Space, Enter or F fills. X crosses. Hold Space and press arrows to paint along a line. M or Tab switches tools, U or Ctrl+Z undoes, and Escape returns to the list.
