The puzzles below are current daily and contest puzzles. These puzzles are competitive and you have to register to solve them and participate in the competition. To register click Login link in the top right corner.

You can use the scores page to see the results of other competitors for the daily puzzle.

All the puzzles from the previous days are available at our archive page. Puzzles which are older than 5 days do not affect the score table and can be attempted without registration.

Alternate Loop

Author: Anurag Sahay

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Draw a single continuous loop in the grid using horizontal and vertical line segments so that the loop visits every square exactly once. It should not cross or overlap itself. Circles should alternate their color while following along the line.

Example puzzle

Grid control: To draw a line press the mouse button at a start cell and move mouse to another cell holding the button. More details about grid control are at the help page.

Inverse LITS

Author: Andrey Bogdanov

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Shade some cells so that in each region there are exactly four unshaded cells that form an L, I, T, S, or O tetromino. Two unshaded tetrominoes of the same type shouldn't share an edge. All shaded cells should form a single connected area without 2×2 groups of cells entirely shaded black.

Example puzzle

Grid control: Click the mouse button at the selected cell to change the color of the cell. Second click will put auxiliary cross sign, which doesn't affect correctness of the solution, but helps visually. You can also drag the content of one cell to another with the mouse. More details about grid control are at the help page.