Reviving is just a typo. Revealing, i meant.
Boss rooms are surely unpredictable, as they should be in roguelike games. But. With this mindset you'll reach the wall much faster. Floors are small, and that's the problem. The game difficulty rises too fast and more things depend on sheer luck. Not only in rewards, but in mines also. Right now, the only winning strategy is to be damn good at minesweeper. It's not a bad thing itself. It's just that those who are damn good with mines are small in numbers. And the rest of players, who are mediocre, are being overwhelmed too fast to just rage quit the game.
So, you need to make levels bigger to get them involved. And you need to create a few winning strategies for them, to compensate for their lack of skills. With this in mind, you add different builds, like (just press anywhere) tank, (mark me half of mines) ranger and etcetera. Still, you also want to prevent any of this builds from being silver bullet. So, you make boss modifiers like "Rolling snowball" (0 initial damage +1 damage for every exploded mine) or "Rogue earth" (some cells can't be flagged), which target one exact build at the time. But you don't want to just kill player "because of F U, that's why", you wanna let him struggle. Even if player dies, you wanna let him feel "Damn, I was this close to victory". So, you allow players to spend some reward on insight status, which allows to see some of the boss modifiers (and, also, hidden rooms/paths). And add some items that allow players to somewhat compensate the weakness of their strategy. You make the items weak enough to be ignored most of the time, yet common enough to be prepared in floor's time period. Players should feel like they have a chance.
You also want to let experienced players to take shortcuts to higher floors faster. Say, let them have high risk hidden path. You can make it in a funny way. Say, make the first floor to consist of half-solved puzzles. And let player to pass hidden path if he unmarks and explodes 2 marked mines. Or something like that.
Also, can you please make an outline for open cells a bit closer to background color. As it is now, it stands out too much and make it harder to concentrate on numbers. Especially, if one have astigmatism or other health issues.