You choose your character from 4 (+1 that you can unlock later into the game) different starting classes (Knight, Adventurer, Aristocrat, Sorcerer and the Transcender) and then you can take 2 NPCs out of the 12 existing souls that you find throughout the game. Afterwards you start exploring the various dungeons called dark sanctuaries. You use bonfires to fast travel from location to another in a similar way as the souls series way of transportation, and defeat various enemies and bosses whilst collecting and crafting stronger equipment. According to the game site there are multiple endings affected by your choices and your class though i haven't confirmed this.