Gantz

Kei Kurono's life takes an unexpected turn after his death, as he finds himself trapped in a game where he must fight against green aliens and robot monsters. The primary objective is to survive, but the stakes are high, and failure is not an option. This game, orchestrated by a mysterious black orb, pushes Kurono's skills, morals, and will to their limits, forcing him to confront the harsh realities of society.