Arcade puzzle, retro arcade, and casino. These are the three most popular categories of mobile gaming on 3G phones, according to M: Metrics, the "mobile gaming authority."
M: Metrics and I-Play, a company that makes, markets, and distributes games for cell phones, have released data suggesting that most games played on 3G enabled mobile phones are casual.
3G refers to the "third generation" mobile phone technology that allows both voice and data transfer to operate at very high speeds at the same time. Mobile game developers have been anxiously awaiting the new technology to become widespread, assuming that its introduction would herald a demand for more high-intensity and bandwidth-hogging games on mobile devices.
In contrast, casual game play has been a dominant force on both 2G and 3G networks.
Designing successful titles for mobile phones faces the difficulty of adapting to odd hours; most people don't spend thirty or forty at a time playing on a phone. One of the main suspects for the success of casual games is the ability to play for five minutes at a time and pick it back up later with no real loss.