Dungeon Climber

Ryan, a 19-year-old boy suddenly woke up with darkness surrounding him. He can't remember any person's face, voice or name but still has memories of them. Even his family fell victim to this. When he stood up and wants to get to analyze everything a loud roar interrupts him. He then has to eliminate the coming danger to survive in the dungeon. He aims to go up to the top floor, maybe he will get his wish granted to go back to earth?