Another World Mall

[Simulation shall commence.]On this fateful day, the world was stunned by the appearance of ancient animals that were supposed to have gone extinct for millions of years. Huge sinkholes appeared in every corner of the world, becoming a tunnel for the ancient animals to emerge to the surface.Humans have found an answer to one of the biggest mysteries in human history. Hollow Earth is real. Here, humans will wrest their lives to explore this new world that has existed for thousands, if not millions, of years underneath them.Before the start of his exploration, Clovis came across a place called Another World Mall.'Dwarven Sword, Magical Elven Clothes, or Giant Race Toy? Everything can be found in this Another World Mall.'As an aspiring Subterranean Explorer, how would he utilize this Another World Mall' to become the greatest explorer of all time and find the truth about the simulation?