My group has been playing Kingdom Death: Monster since January.
It's like a really fucked up Monster Hunter meets Dark Souls game. You have a settlement phase where you are basically in your "town" and build buildings, craft equipment, and innovate your society. Then you go into a hunt phase where you are tracking down a specific monster to kill and various events can happen that can be good (find equipment, gain stats) but can also be really bad (someone can die, equipment can break). If you make it through the hunt phase, you start the showdown phase where you fight the monster. The showdown phase takes place on a very large 2'x3' board with a grid where you place terrain tiles (fallen pillars, bushes, corpses) that you can interact with, and you fight the monster which follows a really cool AI system through cards. Some monsters have really cool mechanics where there is a good chance you will lose the first time you fight them, but once you figure out their mechanic, it will be a much smoother ride the next time you fight them -- just like with some video game bosses.
The game is extremely unforgiving, but once you figure out that you have to game the game and manipulate the AI decks with abilities and equipment, it will start to click. Learning not to get attached to any individual character also helps, as they will probably die before they reach max level, so make sure you breed them so you have more babies to send out later on.
The downside to the game is there is an absolute shit ton of information to keep track of: crafting materials, equipment, survivors (your people) along with their lineage and surnames, who has fucked who and how many kids they've had, what they've killed as individuals, tons of passive abilities gained that affect everyone, unlocked settlement locations (buildings), game timeline, etc, etc. Like in my game right now, we have about 30 survivors, and each one of those mother fuckers has their own dedicated stat and history sheets. It can become difficult to manage later in the game when you're trying to determine the best people to send to a showdown based on the available equipment you have. It also helps immensely to have gone through the showdown before so you know what to expect.
Is the game for everyone? Absolutely not.
Is it worth the current $400 price tag? I don't think so.
Is it a good game? Yes, it's a great game that is very brutal, and unless you are willing to lose and restart quite a few times, you won't make it over the beginner's hump.