By Darren Waters
Technology editor, BBC News website, San Francisco
The mobile games industry has long been the poor relation of the PC and console markets, but a combination of new technology, services and investment is fuelling optimism that mainstream adoption is not too far off.
Mobile games are embracing 3D
Ask anyone to name a mobile phone game and the most common response will be Snake or Tetris.
And while the classic Russian puzzler is the world's most played and downloaded mobile game it is not an accurate reflection of the industry.
At the Game Developers Conference in San Francisco this week the leaders in the mobile game industry have been preaching optimism about the future.
"This is still an infant industry, but it is growing quickly and expanding fast," said Rob Tercek, chairman of GDC Mobile.
"We are looking at an industry that is a $5bn (£2.5bn) industry overall, not bad for one that didn't exist 10 years ago," he said.
But for developers and publishers the mobile games industry is unpredictable.
"Some companies are very profitable, many others are not," said Mr Tercek.
Many titles rely on known franchises
"Ninety percent of publishers are losing money," Michel Guillemot, head of Gameloft, the world's largest distributor of games, told the conference this week.
His firm is one of the few companies to have healthy revenues - $141m (£72m) last year -and Gameloft sells two games every second.
He told BBC News that the industry was in transition as consumers waited on the next generation of devices, which are hitting the market this year.
"The launch of super high end advanced handsets will drive mobile game sales," he said.
The Nokia N Series, the Apple iPhone and Google-powered devices will bring about a revolution in mobile gaming, he said, with the power to deliver 3D gaming experiences, multiplayer games and control through touch.
"Touch screen is going to bring a revolution in the fact we are removing the interface.
"Our creators are very enthusiastic about touch; you can play games with your hands, your finger or your pencil. It is going to bring a completely new experience."
Many developers are excited about the iPhone's potential, even though Apple has made no statements about gaming on the device.
Guillaume Rosier, director of editorial marketing at Vivendi Mobile, said the iPhone's interface would be "fantastic for gaming". But the firm would not confirm or deny that it had games for the device in production.
Many expect Apple to open up the phone to game developers in the near future.
More and more handsets are shipping with built-in graphics acceleration, giving the phones the power to deliver 3D graphics.
David Harold, of British firm Imagination Technologies, which delivers graphics acceleration technology to chip makers, said: "A lot of mobile gaming content is casual and 2D and easy to write.
"But we're enabling 3D content to run on mobile phones, comparable to a Dreamcast or PlayStation 2 in terms of performance."
Imagination Technologies is working on technology to bring the sort of graphical effects seen on PCs and latest generation consoles to mobiles by 2009.
"You can't do advanced 3D in software; it's way too demanding on the system and it would run way too slow," he said.
Developers are also learning to exploit phones to usher in a new way to control the action on a phone.
Mitri Wiberg, founder of game development firm Polarbit, said tilt control in games added a new interactive experience.
Nokia has recently opened the previously inaccessible accelerometer feature in its Nokia N95 phones to developers.
"You can do an awesome amount of things in games with tilt," said Mr Wiberg, whose firm has developed a racing title in which the car is controlled by lifting or dipping the phone.
US firm Gesturetek has developed software which uses a phone's camera to interpret how the phone is being moved; translating gestures into action.
Vincent John Vincent, president and founder of the firm, said: "Being able to do natural movements, not just hand but also full body movement is the way forward.
"It's a lot more natural with gesture and movement," he said.
The technology is embedded in phones released by NTT Docomo in Japan and allows gamers to move the phone, forward and backward, shake it, and roll the device to control action on the screen.
The mobile games industry believes it now has devices on the market which can offer gaming experiences comparable on many levels to home consoles.
Mr Guillemot said phone hardware was evolving five times as fast the home console market.
"In five years time we will have phones with the capability of home consoles of 2005," he said.
Jaako Kaidesoja, director of games at Nokia, said: "If you look at the overall phone roadmap in terms of technology you can see the graphics improvement and 3D acceleration making a difference and they are getting closer to consoles.
"But you have to remember the context of playing mobile games. We are not seeking a similar gaming experience with dedicated gaming handhelds."
Anssi Vanjoki, Nokia's executive vice president of markets, said:"These mobile devices when turned into computers will allow completely new genres of games to be created.
The connected presence and 24/7 nature of being able to reflect your own context can change the way games are played.
"We can mix reality with virtuality and make games where you participate time and place independent or rather time and place dependent - where you are, what you do, who are your relationships."
Mr Guillemot said mobile game developers had only "scratched the surface of what was possible."
"Whatever people say there is a market there. "We are targeting the 21st century audience. This audience is expecting to have a top quality gaming experience on their phones just like on their console at home."