About Fill Line : one line puzzle game

You trace a single continuous path across a grid, filling every square without lifting your finger or crossing your own line. Start on the marked block and drag through empty cells until the entire board lights up. Early puzzles on small grids teach you the basic mechanic, but later levels introduce larger boards and tricky layouts that force you to plan several moves ahead. One wrong turn leaves a square unreachable, so you backtrack and try a different route.

What keeps Fill Line engaging is the balance between simplicity and head-scratching complexity. There are no timers or lives—just you and hundreds of grids that demand careful observation. Whether you play a quick round on Poki Games during a break or tackle a dozen puzzles in one sitting, each solution delivers a quiet spark of satisfaction when the last square fills and the board glows complete.

How to play Fill Line : one line puzzle game

Mouse (desktop) / Touch (mobile) – drag from the start block through all empty squares
Fill every square with one continuous line
You cannot cross your path or revisit a filled square