SAN FRANCISCO • There are video games that go viral overnight, causing people to coop themselves up at home for days to play.
But the opposite has happened with Pokemon Go, a free smartphone game that has soared to the top of the download charts: It has sent people out into the streets and parks, on to beaches and even out to sea in a kayak in the week since it was released in Australia, New Zealand and the United States.
Shares of Nintendo have soared 59 per cent in Tokyo since last Thursday's close, with the firm's market value rising by more than US$10 billion (S$13.5 billion) in just three trading days.
The "augmented reality" game - based on the 1990s Japanese franchise - has played a role in armed robberies, led to the discovery of a body and resulted in minor injuries to fans.
The game - in which players try to capture exotic monsters - uses a combination of ordinary technologies built into smartphones, including location tracking and cameras, to encourage people to visit public landmarks, seeking virtual loot and collectible characters that they try to nab.
Players use a digital map to traverse the physical world, searching for cartoon creatures that surface at random. People look through their smartphone cameras to find Pokemon. When an animated creature appears, they toss Poke Balls at it until it is subdued.
But the game's public nature is also causing unforeseen side effects, attracting crowds that disturb homeowners, and creating opportunities for criminals.
Highlighting a dark side to its popularity, the game was used by four teens in Missouri to lure nearly a dozen victims into armed robberies, police and media reports said.
Social media also buzzed with reports of players who suffered minor injuries from tripping and falling while glued to their cellphones, and minor incidents while driving and looking for Pokemon. And one user, Ms Shayla Wiggins, 19, discovered a body near a bridge while she was searching for a Pokemon character near Riverton, Wyoming.
Nevertheless, five days after its release, the game is on more Android phones than dating app Tinder, and its rate of daily active users was neck-and-neck with social network Twitter's, according to analytics firm SimilarWeb. It has also topped Apple's app charts.
The game is being played an average of 43 minutes a day, more time spent than on WhatsApp or Instagram, Similar Web added.
High demand crashed the app's servers in Australia yesterday, and attracted safety and trespassing warnings from police.
"(Western Australia) police have received numerous reports of Pokemon around the state. Rest assured - we're gonna catch 'em all!" quipped the police force on Facebook, using the game's tagline.
But the police warned that "I was collecting Pokemon" was not a legal defence against a charge of trespass, especially if locations highlighted by the game were inside people's homes or in restricted areas.
NEW YORK TIMES, REUTERS, AGENCE FRANCE-PRESSE