Cute art and interesting take on the whole "minesweeper" concept, not what I imagined after reading discription of the game, coz well, it doesn't say much(or anything at all). So I figured I'll write review on my opinion about game mechanics and such.
First of all, the difference from normal minesweeper is that the MC and all NPC move around the map and to open the tile you need to get near it first.
To interact with NPC you need to be on the same tile(they move around the map, so catching them can take few turns, also game has a great mechanic which keeps them in place if you are choosing to move in the same tile they are on), gameplay is made so that you can ask any NPC to use their abilities to help you reach mission objective, among them are scouting(opens one-two tiles near the choosen destination of NPC, yes, they need to walk to the tile first before using it), harvesting, combat and others. After using ability NPC goes into cooldown mode where you can't request them to do anything.
As I mentioned before NPC move around through save tiles and while moving through event tiles (tiles which have enviroment where an event can happen) sometimes an event starts, if MC reaches that tile before it ends he will be able to "see" what happens there. NPC never move to hostile tiles, so they exist pretty much only to trip MC(every mission has turn counter which shows how many turns you have to finish mission, every move costs 1, and every mistake of choosing wrong tile costs 10)
Well that's pretty much how everything works, hope it will be helpful. Now to my personal opinion:
From the mechanics I didn't like it's that NPC can move through safe tiles you didn't open, while it can be helpful sometimes to figure out where a safe tile is, it feels that's the only reason MC plays minesweeper is because he wasn't given a proper map and nobody wants to share what they know(the dream team level teamwork right here).
The game is pretty challenging if you try to earn stars(not sure what they do, and if they do anything at all besides adding to achivements, didn't play far, could be nice if gathering them opened new content thought). I'm no fan of NTR or voyeurism so the whole concept of "MC works his ass off while everyone else is having fun while occasionally helping" is not for me(inability to join the fun is quite offputting). Not sure how the whole rival thing is going to work when the only thing MC can do is watch since he always appear from the wrong side of the "wall".
Oh right, I read Apo_Icarus's review and I don't see why futa can't be also love interest, expecially with all that nun and little brother thing.
Anyway, good luck to the dev with this project.