Fill Line : one line puzzle game
About Fill Line : one line puzzle game
Fill Line challenges you to draw one single continuous line that passes through every cell in a grid exactly once — no backtracking, no gaps. The constraint sounds simple but the puzzle design creates configurations that require genuine insight to unravel.
The game starts with small grids where the single path is discoverable through trial and error, then grows into complex mazes where only careful planning from the start reveals the one correct route.
Play free in your browser — no download, no sign-up required.
How to Play Fill Line : one line puzzle game
Click and drag to draw a line starting from the marked cell.
The line must pass through every single cell in the grid.
You cannot lift the pen or cross a cell you've already visited.
The level is complete when all cells are filled with your one continuous line.
If you get stuck, release and start fresh from the beginning.
Tips & Strategies
- Identify forced moves first. Some cells have only one possible entry/exit direction — trace these forced segments first before tackling the ambiguous sections.
- Avoid creating isolated regions. If your line separates part of the grid from the unvisited rest, that section becomes unreachable — dead end.
- Work from corners inward. Corner cells have only two possible directions — one in, one out. Handle them first to reduce the solution space.
