There is no instructions on how to play? You assume everyone knows what Sudoku is
Ok, so you've got 320 puzzles (20 stages of 16 levels). I must say, this is the most boring game I've been able to find lately. There's nothing horror related (Unless you consider A single skull as scary.) There's no threat on losing. No jumpscares or anything to give this game shine.
The least you could do is have a level skip to get to the more difficult puzzles instead of playing puzzle after puzzle to get to something actually worth a challenge. Better luck next time.
I've played 10 levels and the 'puzzles' are still not Sudoku, simply finished Sudoku with a few numbers missing. If you feel compelled to start your 'Sudoku puzzles' at such a ridiculously easy level then you have to include some way to skip levels and start at a higher difficulty. I don't have the patience to play the whole game through but I expect that, if I did, I would enjoy at least the last 30 levels or so. Since I would have to play 170 useless levels to get there, though, I'm afraid your game is a failure in my eyes.
the starting difficulty is to low and it raises to gradually... tl;dr it gets boring
the fact that you have to click 9 times to get a 9 is annoying.
other then that it's a decent sudoku game
I liked the Timed concept and the theme is good but could be more involved....my major problem is that anyone who has done any sodukos before should have the option of skipping the first set......it was way to boring to even get past that to see if 2 should be skipped......sodoku is popular enough that users should be able to chose the difficulty level....let me find the point where there is a challenge and play from there and it will be fun.