The iPhone has virtually no buttons but it has already emerged as a significant threat to Nintendo and Sony in the portable games market.
Major game developers including Electronic Arts and Sega have jumped onboard to create elaborate titles that rival the Sony PlayStation Portable and Nintendo DS in terms of graphics and gameplay.
On the iPhone App Store, where users can access a range of free and paid-for third-party applications, games have fast emerged as the most popular offerings, with more than 1500 titles to choose from.
This is significantly more than the total selection of games offered for the DS and PSP combined.
The App Store, which was launched only in June, is the secret to Apple's successful video game debut. It allows anyone to create games and sell them directly to users for a low price, with little overheads and without going through publishers or traditional retailers.
Unlike traditional gaming experiences that revolve around button mashing and joypads, gameplay on the iPhone centres on the large touchscreen and built-in accelerometer, which allows players to control the action by tilting the phone.
Despite the absence of buttons, the iPhone appeals to gamers because it allows them to have a single device capable of functioning as their phone, music player, video player, portable computer and game machine.
"In terms of the games we're working on now, I'd say the iPhone is comparable to the PSP or DS," Gonzague de Vallois, executive at iPhone game developer Gameloft, told The Guardian.
Apple CEO Steve Jobs has said he expected the iPhone (and iPod Touch, which can also access the App Store) to emerge as a viable gaming device this holiday season. More than 50 million iPhone games have been downloaded so far.
Another Apple executive, Greg Joswiak, said in a recent interview with Stuff.tv: "The graphics capability is greater than the DS. We have multitouch, the screen is larger and there's an accelerometer. And we have the App Store. I think it's the future of gaming."
Already, developers are pushing the boundaries and transforming the iPhone into a motion-sensitive controller for PC games. One new app, iFun, turns the iPhone into a motion-sensitive Wii remote, allowing users to play sports games such as golf against each other over the internet on their PCs.
One of the world's largest game publishers, Electronic Arts, responsible for best-selling franchises such as The Sims, has published seven games for the iPhone including Scrabble, Tetris and Spore: Origins.
