Reborn as an NPC: I Became the Strongest Player!

Monsters are rampant and humans are forced to become players. After clearing the game, the ending turns out to be that humanity has perished? As the last survivor in this world, what kind of ending is this? If I do it again, I must become a man at the top and change the outcome of humankind's demise. Don't ask, I want the equipment! I want the school beauty too! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.