A computer game developer must have a clear understanding of the market and the different game styles favoured by each sector. Online games tend to involve role-playing, with a strong social networking element. Computer-based games are often single-player games that have a good story line and a refined core game mechanism. All games must conform to the language of computer games. For instance, the motion-control sensor must be similar in range to other games with motion-control sensors. 'It is a balance between innovation and traditional player acceptance,' said Steven Wong Tak-kuen, programme manager of M-Inverse Holdings. 'We want to be innovative but we have to work out what the players already know and how they play.' Ideas for computer games go through stages. Initial ideas might seem good but are impossible to implement upon investigation. Many games are built first as prototypes, usually with one or two layers of the core-game functionality and rudimentary graphics. These are then tested to ensure they are fun and that the core mechanism is workable. Successful prototypes are developed further and then presented, along with detailed documentation, to prospective game publishers. Good ideas are hard to come by and many are offered unsolicited by well-meaning game fans. 'It's funny, sometimes people come up and say 'I have this great idea for a game' and usually it's just horrible,' said James Wong Kai-on, co-founder and game designer of Playpen Studios. 'The ideas range from derivative copycat stuff to things unmarketable and inappropriate.' Mr Wong gets his inspiration from his team most of the time. 'Seeing what they are capable of triggers new ideas,' he said.