Summary:
- The article discusses a GPS-based game developed by the team behind the classic video game series "Metal Slug" over 15 years before the release of "Pokémon Go."
- The game, called "Metal Slug Mobile," was designed to use GPS technology to allow players to explore the real world and encounter virtual enemies and items.
- However, the game was never released due to technical limitations and concerns about the potential impact on players' safety and privacy.