SumSudoku: Killer Sudoku is a crossover variation of Sudoku and Kakuro, offering addictive logic puzzles that will keep puzzle fans entertained for hours. With a 9x9 Sudoku grid and areas surrounded by dark borders, the objective is to fill all empty squares so that the numbers 1 to 9 appear exactly once in each row, column, and 3x3 box. Additionally, the sum of the numbers in each area must be equal to the clue in the area's top-left corner, and no number can be used in the same area more than once.

The game provides helpful features such as showing possible sum number combinations in an area and pencilmarks for temporary placement of numbers. It also includes a Weekly Bonus section with an extra free puzzle each week. With multiple difficulty levels, a continuously updating puzzle library, and unique solutions for each puzzle, SumSudoku: Killer Sudoku offers endless intellectual challenge and fun. It sharpens logic and improves cognitive skills, making it suitable for puzzle enthusiasts of all ages.