The objective of PG Sudoku for Android is to fill a 9x9 grid with digits from one to nine so that every horizontal and vertical line and every large 3x3 square contains only one instance of each number. It generates every puzzle 'in fly' and ensures that each generated puzzle is unique. PG Sudoku for Android provides four different levels of difficulty: easy, medium, hard, and impossible. First three levels ensure that every generated Sudoku is solvable without guessing. The last 'impossible' level requires guessing few numbers in order to solve Sudoku. The game is saved automatically when you exit the application. The user can also input and resolve custom puzzles.