Fill the blocks with one line

A fresh take on the classic one-line puzzle genre, this game asks you to traverse an entire grid while touching every filled cell exactly once. The twist lies in the layout: each colored block must be included in your path, and the route can never cross itself or branch off. What starts as a gentle warm-up quickly evolves into a brain-teasing maze of angles, loops, and dead ends that reward careful planning over speed. As the boards grow denser, you'll need to think several moves ahead, spotting forced turns and anticipating blocked corridors. The minimal visuals keep your focus on the logic, while the subtle satisfaction of completing a tricky route drives you forward. Whether you have a minute or an hour, this puzzle offers a neat pocket-sized challenge that sharpens your spatial reasoning with every attempt.

WaffleMath

Fill the blocks with one line

Common Core State Standards

Every game supports specific Common Core standards. Browse the full standards library.

MP3Argue with math MP1Make sense of problems MP7Use structure MP4Model with mathematics MP2Reason abstractly 1.G.A.1Shape attributes K.G.A.1Position words 2.G.A.1Draw shapes with attributes

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2nd Grade · 3rd Grade · 4th Grade

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What is Fill the blocks with one line

A single line, a full grid, and a simple rule: cover everything without breaking your stroke. This puzzle asks you to find a path that touches every colored square, with no shortcuts and no revisits.

How to Play

Click or drag to draw a continuous line that passes through every colored block on the grid. Once the line starts, you cannot lift your pointer or revisit a block, so plan your route before you begin.

Tips for Playing

Start from a corner block if possible, as corner tiles often restrict your movement.
Look for blocks with only two open neighbors—they force your line to pass through them in a specific way.
Avoid creating isolated clusters that you can't reach later, since you must cover every block.
If you hit a dead end early, retry with a different starting block rather than forcing a long path.
Mentally trace potential routes before committing, especially on denser layouts.

Frequently Asked Questions

Can I lift my finger or mouse mid-drawing?

No, once you start drawing, the line continues until you either finish covering all blocks or run out of moves. Lifting resets the attempt.

Is there a penalty for making a wrong move?

There is no time pressure, but a wrong move that prevents covering all blocks forces you to restart the level from scratch.

Do I have to pass through every empty cell as well?

No, only the colored blocks matter. The line can travel through empty cells, but it must touch every colored block exactly once.

What happens if my line crosses itself?

Crossing is not allowed because the line must be a single continuous path without overlaps or junctions. Such a move will invalidate the attempt.

Are there hints or solutions available?

The game typically does not provide built-in hints; you rely on logical deduction and experimentation. Retrying from a different start often reveals the solution.

Can I play this on a touchscreen device?

Yes, the dragging control works with both mouse and touch, making it suitable for phones and tablets as well as desktops.