I really like the concept and the way you gave minesweeper a lot more atmosphere or theme. The visuals are very pleasant and the music and sounds go along in a peaceful manner.
However, I feel that the gameplay is a bit of a downgrade from the reference, as it is a bit too slow, and sometimes I feel that the knight is just dragging a litle bit, like I'm scouting, I see that one is open, and then I grab the knight , make them move through the place to open the things, change, check the new ones, and repeat.
I liked it anyways, but I think with a litle bit more time it could have introduced a new mechanic that could make it shine (don't know that that could be though).