The game "Sudoku Rexarich" by the studio "Brotherhood" [Developed using RPG Maker VX Ace].

It's not difficult. To each their own, as you said. As a gamer with over 20 years of experience, having seen all sorts of things, I'm unlikely to play Sudoku, Tetris, Shadowverse, or similar games in 2018. I went through that phase back when I was first learning to use the Windows operating system. Although I don't deny that your game might interest someone, say, grandmothers, retired women, or forty-year-old pregnant women. So, there's no need to despair just yet.