Pretty neat take on minesweeper! For the most part, the game is very addictive and fun thanks to your gorgeous presentation and satisfying gamefeel, and the introduction of battle segments to replace instant death when you trip a mine was a novel concept to differentiate it from your typical minesweeper clone. I really like all the cool and juicy touches the game has, like the way the screen shakes and the bubbles that appear from the scuba helmet. I had a lot of fun playing!
If I were to have any feedback, it's that as neat as the combat segments are at first, they end up feeling like a silly gimmick due to how simplistic they are and how they fudge the numbers (the health bars mean nothing because damage is always a certain percentage). And after all, as long as you play well, you'll never encounter combat, so it ends up feeling like a waste to have this new element only exist as a punishment? Maybe it'd be better if you always encounter a fight at the end, but the difficulty depends on how well you did in the level beforehand? I dunno, just something about it felt rather token in its current execution.
Some of the other mechanics like how you won't trip kraken tiles if they are within your 3x3 uncover seems to make the game too easy as you just flag them immediately instead of having to math it out to figure out what's what. I guess it makes sense because you wouldn't want a user to get penalized when they have to uncover a large area...but then why do you make it that they uncover a whole area instead of just 1 by 1? Again, similar to the minigame, it feels like you've added something new but it just ends up not necessarily enhancing anything.