Recent reviews by MightyPion

Well worth the price in its current state.

As a TLDR, this is a less random/punishing variant of Darkest Dungeon (clearly its spiritual liege).
Currently early access, so limited to 3 campaigns.

There is a considerable variety of minions (heroes essentially), which you will use to battle the enemies.
You can equip these minions and level them up, and obviously, minion composition matters a lot.
One can try to go for a mostly stress based build, a mostly kill based build, or for various things in between.

This game has some strategies which would not be possible in darkest dungeon. For example, you can totally create 4 level minions, of which several may have a suicide skill, and just blow up a particlarly strong enemy party to weaken them for your actual force. Also interesting is that brains are an equipment slot. Brains of different levels can be used to directly level a newly created minion to the desired level, which greatly takes the sting out of losing an important unit.
There is no grinding either.
I would recommend diving straight into the current beta, which makes leveling up monsters a lot more systematic.
Another difference to darkest dungeon is that you will see what your next fight will be, and you can thus use appropriate units.