No. Every sudoku in Minimal Sudoku is guaranteed to be solvable. If you can't finish one of them, you probably made a mistake earlier. Of course, one should now that Minimal Sudoku only marks obvious errors, i. e. when an inserted digit is already filled in the same row, column or block.
Don't give up! There are unlimited sudokus, so you might just as well start a new one and do it better this time. 😊
If you really think a sudoku is not solvable, send me a screenshot of it.
Yes. There is no internet connection needed for Minimal Sudoku. The sudokus are created on the fly right on your device.
The download of the app is free of charge. If you are a very keen Sudoku player, you can purchase the difficult and very difficult levels for $ 0.99 or € 0.99 via an in-app purchase. That's a once and for ever purchase, you will never run out of hard levels.
Sure! Follow these steps:
You then should be able to play the hard levels again.