It's that time of the year again when everyone in the world of mobile gaming gets very, very excited.

And why not?

Now into its sixth year, the PocketGamer.biz Top 50 developers list is the accolade that everyone is clamouring to be included on.

So, kicking off GDC 2015 in style with the winners at our VIP launch in San Francisco on Sunday, over the next week, we'll be revealing the companies who are defining the ever-changing world of mobile gaming.

They're everywhere

Of course, we're not going to spoilt the surprises quite yet, but to set the scene, there are some significant trends to report.

For one thing, our list is now truly global, demonstrating you can find world-beating mobile game developers everywhere from Helsinki, Tokyo, San Francisco, London, Seoul and Shanghai to less well known cities like Karlsruhe and Aarhus.

A more subtle change is the maturing of the market. With mobile game revenues in 2014 estimated to be $25 billion, it's clear that the early days of triple-digit growth are over.

Instead, in future, developers will be competing for slices of a relatively fixed pie.

And much of that pie is already claimed by companies with annual sales of more than $1 billion.

Quality counts

That's not to say that new games and new entrants can't shake up the system, however.

As demonstrated in Japan and China, relative newcomers have entered the app stores and claimed the #1 top grossing slots of these highly competitive and lucrative markets.

Yet, more generally, in 2015's list, we're been less focused on headline financials compared to previous years, concentrating more on f the quality of games; something that in future will only become a more important part of delighting the mobile gamer.

And, after all, that should be the starting point for every mobile game.