During summer vacation a group of fifteen children discover a mysterious man living in a cave surrounded by high tech gadgets, the man claims to be a game developer, creating a video game with a giant robot defending Earth from fifteen alien invaders. He asked the children to test the game for him and they agreed.
Sekai-kei stuff should get you to the point where you care enough about the characters' wellbeing that you can see yourself balancing their personal lives with the entire world's existence. Kitoh Mohiro's writing gets so bleak that you just want the entire world and the characters to an hero so they can at least end their misery.
