Nonogramm - Japanese crossword puzzle "Lemon" ("Griddler", "Pic-a-Pix", "Crucipixel", "Hanjie") 35x25 solve online for free
Nonogram looks like a square or rectangular grid that has on the top and left sides some numbers that indicate how many groups of black cells are found in the corresponding row and how many grouped black cells are contained in each group, they are are used to fill the grid to form a specific design. The groups are separated by at least one white square.