
Audience
There is a huge difference between an educational game for little kids and an 18+ rated zombie shooter.
Defining the audience is part of the initial creative process. Even if it seems such as a consequence of the kind of game one wants to make, it is important to spend some time thinking about it and having a clear idea of who is going to play the game. The kids/adult example is an easy one, but identifying an audience means asking yourself questions such as who is interested in this game? Which other similar games does he or she play? What are they expecting from a new game in their favorite genre?
Mere demographics are still an important factor in defining an audience, but in our modern world, amazingly, pretty much everyone plays video games and there's no such thing as a young hardcore gamer or an average casual gamer.
These are concepts from the past that it is important to leave behind. Everyone is a potential gamer in today's world, but each and every gamer is interested in very different game experiences. Internet and online communities give game developers an incredible tool to find out about people's desires and fantasies in terms of what they'd love to play. User research is done by many developers, submitting rough concepts, trailers, or marketing materials of games that don't yet exist to test and learn from those desires.
Video game audiences are also constantly evolving. There is a great article written by Meg Jayanth (the writer behind 80 Days) for The Guardian in 2014 titled:
(https://www.theguardian.com/commentisfree/2014/sep/18/52-percent-people-playing-games-women-industry-doesnt-know). Give it a good read! Industry reports available online can also give you a great idea of the different (and, sometimes, unexpected) types of audience out there.
Casual players who have a few spare minutes on their commute is incredibly more accurate than an average casual gamer.
Hardcore players who grew up playing strategy games such as Dune II and Fallout Tactics are not quite the same as hardcore strategy game players.
A more precise target audience definition is extremely helpful because it gives you something to design around already. Just look at the information contained in casual players who have a few spare minutes on their commute. You don't only know that your game is for casual players, you also know that the average game session should last no more than a few minutes and that the game might have some problems working online, as commuting usually means unstable mobile networks.