Darkest Dungeon is a side scrolling, turn-based role playing (RP) management game with a macabre theme. The main plot is that you are a relative of some old, eccentric rich dude. The old dude got bored, so he decided to spend the entire family fortune on summoning demons and evils into the family estate. Now you return to the estate to help clear it out with the help of some mercenaries.
The game play is a team of adventurers going to locations with specific goals in mind. Once they accomplish — or just as likely fail — their mission, they return to the hub city to tend to their wounds. These wounds can be physical, like diseases, or mental, like kleptomania or schizophrenia. This is just another part of the RP aspects of the game. Your adventurers of course level up systematically and with their increased stats, they can get buffs or debuffs. You should never get that attached to any one character. In the early missions, it is easy to keep your mercenaries alive, but as the game moves on, you will end up cycling through many new recruits.
There are several character classes that really do feel unique. For instance there is a character that is partly monster. You can make him transform so that he can save the party in a bad situation, but he will cause their sanity to plummet. If their sanity gets too low, they develop nasty mental traits like a love for blood or a desire to kill their party members. These only help to make their friends sanity go lower and for them to have their own breakdowns. Once the snowballing begins you should just try to get out of the mission because you will almost certainly lose your employees.
All in all, the game can be a ton of fun, but it also can be a little too hard and depressing. I hate losing parties in any game because no matter what I grow connected with the characters. Also the random number generator (RNG) can sometimes seem to be rigged against you and want you to all go crazy and die. If you are into that sort of punishment, the game is Darkest Dungeon on Steam for $25. This is a game that will go on sale for decent amounts on the summer or winter sale, so I suggest waiting.