Pathfinder: Wrath of the Righteous

You start the game wounded by some unknown means, and dragged into the city square during a massive festival by several guards seeking a healer for you. You are only temporarily healed, but you do get to briefly participate in the festival before the city is suddenly attacked by a massive horde of demons. A fissure forms and you end up falling into it. You awaken to find yourself in a network of underground caves, and need to fight your way back to the surface along with a few other survivors and beings that call the caves home.