This game uses 2D pixel art graphics with a retro feel. So, if you provide a small pop-up window screen function as an Option, the cute 2D pixel art graphic will look prettier on the small screen. And, like the Windows Solitaire game of the past, if this game can be opened as a pop-up window, it will often be convenient to enjoy while doing other work.
I might be the only one who thinks so with these suggestions. I expect that 'Control key setting' option and various other functions will be added in future versions.
The reason I'm making this suggestion is because I think this game is very well made, as if it were made by a professional developer. Kudos to your development skills, I'm looking forward to the next version!! - From an retro game fan who enjoyed your game in Korea