SumSudoku: Killer Sudoku

SumSudoku: Killer Sudoku is a challenging logic puzzle that combines elements of Sudoku and Kakuro. The goal is to fill a 9x9 grid with numbers 1-9, ensuring they only appear once in each row, column, and 3x3 box. Additionally, the sum of numbers in each dark-bordered area must equal the clue in the top-left corner, with no repeating numbers in those areas. Beneficial features include sum number combinations hints and pencilmarks for temporary number placement.