A minimalist bright cohesive design was created for a series of 10 covers for Sudoku collections of varying difficulty levels. In two formats, for adult and children's audiences. A common concept was developed for the series. Colors and shapes were selected to enhance the emotional and visual recognition of the difficulty level; for example, rounded shapes on the panel emphasize the simplicity of solving tasks, while sharp edges of the star demonstrate high complexity of the puzzles. Illustrations were created on the covers for the children's audience. The work was completed in two days.