I'm trying to remember a game I played a long time ago. What I remember:
- Pretty sure it was PS2
- Plot was about a character waking up in a post-apocalyptic Tokyo area after some form of experiment with radio towers went wrong and caused everyone to fall asleep and die. Much of the game is spent exploring how this happened in various ruined areas (in order: a train station, a theme park, a hot springs hotel, and then later a large underground reservoir and dam).
- The main character, for the first arc, finds a little robot backpack with a sentient AI that helps him navigate around the environments.
- There is combat, but it is limited. Most of the game the player relies upon his flashlight and using things like sticks and metal bars he picks up in the environment to fight with
- There was an ambiguously gendered "best friend/rival" character, one of the only actual characters aside from the main character, that messed with the character at the ruined theme park and then later turned out to be a robot.
- The final battle took place with a crane on top of a dam, trying to save some girl who was actually alive.
I remember it not getting much press because it came out at the same time as another game that used flashlight mechanics much better.