The number 13 occurs in many ways when playing the game. These are a few examples:
• The game consists of 13 chapters.
• The flashbacks take place 13 days before the events of Chapter 1.
• There are 13 shops to buy items from.
• When clearing certain missions, you can get an Analog, which there are 13 of.
• The Datalog has 13 submenus.
• To get a 5 star rating you need to get 13,000 battlepoints.
Contributed by aapjes