For now the game only has one game mode - classical 4x4 sudoku but extended into a 3-dimensional 4x4x4 version. This was my first project I decided to get to a more or less finished state just to get through all stages of releasing a small game. 

As a bare minimum, I would like to add a classical 9x9x9 mode to consider the game 'full', however I have some ideas about more game modes I could try. That said, this project wasn't meant to be anything more than an obstacle course and oooooh boy was it one. What that means is I will probably switch to other projects instead of getting bogged down with a sudoku game for a long time (especially if it's of no interest to anyone), so any work beyond adding a 9x9x9 mode is not certain to happen.