Strimko at Retro64. If you’re a fan of Sudoku, and a lot of you are, then you’re really going to enjoy Strimko. Just like Sudoku, you add up numbers to a total sum, without repeating. But in addition to the horizontal and vertical uniqueness of Sudoku, Strimko also has zig zag lines in the puzzle that have to be unique as well. This adds to the challenge for sure, but it also adds to the fun.