Mobile Interfaces, http://www.hitlabnz.org/fileman_store/2005-MUM-MobileUserExperiences.pdf Last accessed 28/05/06

Mobile phone games interact with users differently due to limit screen space and key space. But phones can make use of connected devices to interact with the user for example the camera can be used.
Designing phone games is also hard because phones are different sizes so the design has to take into account how the user will hold the phone while using the application since if the keys are set up badly the user could find it hard to play since the phone isn’t being held comfortably.