Darkest Dungeon is a brutal roguelike turn-based RPG that breaks the spirit of its characters and players alike. It has a unique take on dungeon adventuring and chooses to focus on the psychological stress and effects of dungeon crawling and constant near-death encounters.
There are numerous mechanics present in Darkest Dungeon that new players might be taken aback by. The long-term party management is something that you might have never given any thought to in prior gaming experiences, and it might all be a bit too much to handle. However, taking it all one step at a time and going in with the right mindset can save you from a lot of stress.