Having a Right-click marker for known mines would be nice. Also, the Win and Lose text needs something behind it, so it's legible.
I've clicked on the items in the store, but I'm not sure how to buy them. It's also not clear when money is earned. Is it only after clearing a minefield?
This definitely has potential to be a great successor to Minesweeper, but there's a few minor things that are holding it back, ATM. Fix those, and that'll greatly improve the overall experience.