Here is the full list of all 12 Mine Seeker achievements.
win a game with the maximum board size and at least 25% mines
win a game with at least 25% mines on the field.
win a game by running out of time
you lost 100 rounds
loose with 90 or more percent of cleared tiles
place 1000 flags
Win at least 1 game on every map
... other than me (win a game with maximum mine amount on a board at least 25 tiles wide and long
Win 50 games
Win 100 games
Win 500 games
Win 1000 games