I'm out

A first-person perspective shows a character holding a shotgun, moving through a dimly lit, decaying building with tiled floors and graffiti, then entering a room filled with numerous zombie-like figures. The scene abruptly cuts to an anime sequence where a character with spiky black hair is riding a large, red, pig-like creature across a sandy, stone-walled area, while other characters and a purple, tentacled creature are visible in the distance.