To understand the issues for designing a game with Layar as the platform, a PACT analysis framework  was used to evaluate the application in the context that the game will be played; on local buses in Bristol. The small‐scale project utilised discount usability  and iterative design. Early stage prototypes were evaluated in live situations by the extended project team, which highlighted the following key issues:
Motion sickness whilst using an AR browser
All participants reported a feeling of motion sickness whilst interacting with the Layar based game, including those who didn’t normally feel motion sick whilst reading or using devices in vehicles. It appears that the overlay of information in Layar’s camera view brings about the feelings of nausea, which quickly subside when not using Layar. Motion sickness is still a poorly understood physiological phenomenon but the stimuli that cause it are well documented. These causes are usually isolated to either inertial motion sickness or visually induced sickness [4, 5].
Social issues of camera use
Another observation was that when the phone is held up, people in front of the camera are very aware of being photographed or filmed. The pointing of cameras raises two interrelated issues of privacy  and the claiming of personal social space . The user can be seen to be claiming a particular, indeterminate space and bringing in‐view people into a one way, non‐negotiated relationship. This makes the users uncomfortable, as well as other people on the bus, creating a very difficult situation for the use of this technology whilst on any forms of public transport.
Device and interface issues
There are two specific device issues that came up during testing. First, the lighting on a bus is highly variable, based on the internal lighting and the level of sunlight coming in from the outside, and can affect the experience. Secondly, there is a lag between movement and updating of the GPS data, so the application does not show an entirely accurate representation of where the user is. The variability of the bus speed and irregular starts and stops means that the users’ location can not be corrected for statistically. This leads to a disrupted and broken experience.