Emotiku is a nice and challenging variation of Sudoku.
Similarly to the classic Sudoku puzzle, the aim of the game is to fill the board with 10 emoticons making sure that in each row, each column and each 4x4 block there is one and only one of 10 emoticons.
If you prefer, you can play classic Sudoku, that is, use the digits from 1 to 9 to fill the board. Just access the options menu and enable the "Classic Sudoku" option.
Main features:
thousands of games available, randomly generated without repetition.
four difficulty levels: "very simple", "easy", "medium" and “hard"
hints: during the game it is possible to ask for help to AI and obtain a rule/strategy to use to progress in the solution of the game (especially useful for beginners or at the beginning of the most difficult schemes)
games history: you can see the list of the last games played, resolved or suspended. From here the player can resume a game (only the suspended ones) or replay it again from the beginning.
auto saving: at any time the player can suspend a game in progress and resume it later, even days later. The last game played is automatically saved and can be resumed even after the device has been restarted.