The mobile gaming market is expected to generated up to 50 billion USD by 2015. If this is true and strong performance keeps on, it would be possible by 2020 to even reach 100 million USD.
Of course with gaming, also PC and Mobile devices and their gaming hardware will rise steadily. By 2020 also it is expected to grow into a 50 billion USD industry.
Mobile games are on the rise while PC games and console games are having trouble. Due to the amount of mobile devices and the free gaming option, less and less people are playing their games on PC. While it is true that PC Games usually have better graphics and longer gameplay, for the average player it matters most that the game is free and can be replaced by another game easily.
Still console and PC games are very popular. After all tournaments are usually held with such, and the biggest and best game developers will continue to rely on better hardware than is available on mobile phones.
On the other hand, web games are on the decline. The limits that are set by browser games are just too vast to compare with the beautiful graphics that are possible via other means. It is expected that the sale of mobile gaming software will outpace the sale of all other games by 2050, especially with VR and AR becoming more broadly available.
You could see the different demos for the games made through this link.