On amazon there was a funny comment made, which I think is worth to mention:
5/5 great excuse to get close with a girl. Taught her how to play minesweeper, if you know what I mean.
For the next updates of the game there will be an ingame tutorial added, because many players are complaining about it - they are right, I will try to add an interactive one, so the gameplay is declared in a good manner. Much more important is, that players should be informed of fast-playing modes like the tap-on-number-to-reveal.
Should have thought about that much sooner, I apologize.