Most minesweeper games have a shortcut to to clear any extra tiles around a square if you've flagged the right number of mines, usually shift-click. This would really make the game a lot faster, and I'm surprised it's not in the game.

at first I thought it shows mines left, but still have no idea. or will it be clear with progression?

I would love to ask a few questions about The Simplest Game in the World, if you have a contact email? I would love to be able to complete it!

The idea of nested minesweepers is genuinely great, but there needs to be a rule corner or popup at the start of the level. I'm still not sure WTF the purple crosses do. And the levels where numbers lie are just not fun if I don't understand the rules. When I know them - I start to think; when I'm just ♥♥♥♥♥♥ by every new mechanic without explanation I want to close the game....