Nintendo shares have tumbled after investors gave the thumbs down to its new Super Mario app.
The Japanese technology giant saw $2bn (£1.6bn) wiped off its market value as shares fell by 5% in Tokyo, after Super Mario Run was made available on the iPhone in 151 countries.
It later recovered slightly to close 4% lower.
Super Mario's release is the latest foray by Nintendo into the mobile app market after the Pokemon GO craze earlier this year.
Early signs for the Mario game were positive as it topped download rankings in Britain, Japan, Germany and Australia.
But some analysts are concerned about the $9.99 price tag - £7.99 in the UK - to access the full version of the game.
Another concern is that Android users will not be able to buy it until later.
The Mario game is free to download but only for low-level stages.
That sets it apart from successful app games such as Candy Crush Saga and Angry Birds which typically only charge for in-game items and powerups.
The release is also a risky bet because, unlike Pokemon GO, it is being developed by Nintendo itself, in partnership with mobile gaming firm DeNa.
That means it will enjoy the lion's share of any success or bear the brunt of failure.
Pokemon GO, while based on a Nintendo character, is owned by San Francisco-based Niantic.
Its release marked a change in strategy for the Japanese company, which for years had resisted developing smartphone games or licencing its characters for online play.
Pokemon GO has been downloaded more than 600 million times since July.
Its release produced revenues of $143m (£115m) in its first month but analysts expect Super Mario Run to take about half of that.
Nintendo shares have risen by more than 50% this year as the Pokemon release lifted hopes about its potential for success in the app market.
- Sky News