Japan joined the worldwide hype over the "Pokemon Go" with the debut here last week of the smartphone game that is said to have turned the streets of more than 30 countries a bit more dangerous in recent weeks— not because of violence but distracted people frantically playing the game rather than paying attention to the world around them. Despite a rare government warning prior to its release, the home of the monster characters has already had its share of mishaps associated with the addictive game — including people caught driving while playing the game, a cyclist robbed with her attention all on her smartphone screen and an absorbed pedestrian wandering onto an expressway. Examples overseas have ranged from players falling off cliffs, walking across highways without looking, being lured into isolated spots to be robbed and ramming cars into trees and parked cars.

It has been an extraordinary success, setting new records for downloads and active users. On the day of its Japan launch last Friday, Nintendo’s shares on the Tokyo market soared from ¥14,490 before the game's launch to ¥28,220. It is forcing a rethink about virtual reality and how we interact with video games and devices. It is a remarkable reimagining of a 20-year-old video game that exploits a healthy dollop of nostalgia, too.

"Pokemon Go" is a video game played on mobile devices that combines the video game and TV series with augmented reality and GPS: After downloading the application onto a phone, users search for Pokemon characters as they go about their daily lives. The app uses GPS data — generated in a previous game by the app maker — that locates character in various places such as parks, zoos and buildings. When the user looks at the map, the character's "footprints" are visible as they get closer to its location. When they find the character, it is visible on the phone camera. They then can "capture" it to earn points. This real-world adventure has turned nostalgia for the children's game and show into a massive money maker. Prior to its Japan debut, the game had already been downloaded 30 million times since its launch earlier this month, and was anticipated to become the first smartphone game to generate $4 billion in revenue in a year.