SETTINGS 
Sudoku grid
SUDOKU SIEGE is a numeric puzzle game based on the famous Sudoku grid of 9x9 spaces, where within the rows and columns are 9 "squares" (made up of 3x3 spaces). Each row, column and square (9 spaces each) needs to be filled out with the numbers 1-9, without repeating any numbers within the row, column or square.
Sudoku Siege frame
Unlike a standard sudoku game, in the SUDOKU SIEGE game, each of the 81 spaces is initially empty, but the grid is "surrounded" by numbers that represent the product of the three numbers that make up the corresponding rows or columns of 3x3 squares which they touch. The central 3x3 square doesn't have any product info for its columns and rows, but that doesn't mean it's unsolvable!
How to start (advice)
The easiest way to start solving the grid is to start with 3x3 squares at the corners where you can see the products of both, rows and columns. Since only one of the three row-products is divisible by "5" (the same goes for three column-product), just cross that row and column and put "5" there. The same method you can use for "7" too, but with all other numbers it won't be so easy! Good luck!