1 Angry Birds, no longer soaring so high

Angry Birds was the first genuinely massive brand to emerge in the iPhone and Android era of mobile gaming. Finnish developer Rovio launched the first game in December 2009, and by the end of 2012 the company's titles were being played by 263 million people every month. In 2013, though, its growth stalled. Rovio's revenues had doubled in 2012 to £125.1m, but in 2013 increased only slightly, to £128.4m, while net profits halved.

The latest Angry Birds title, racing game Angry Birds Go!, has not been setting the app store charts alight either, certainly not compared with Rovio's emerging competitors.

2 Candy Crush Saga, the new king of gaming

If Angry Birds has been dethroned as the biggest mobile gaming brand, Candy Crush Saga is probably the contender for its crown. By the end of 2013, 93 million people were playing the sweet-matching puzzle every day: its publisher, King, said the game was played a billion times in December alone. The company reported revenues of £1.1bn in 2013, and this year went public on the New York stock exchange.

Also riding high is one of Rovio's fellow Finnish firms, Supercell, which made £528.6m in 2013 from two mobile games: strategy game Clash of Clans and farming game Hay Day. Elsewhere, Japanese firm GungHo Online made £945m in 2013, with 91% of that coming from a single mobile game, called Puzzle & Dragons.

3 Other birds are available (and flappy)

At its peak, Angry Birds was something of a craze in the mobile world. In 2014, that role was fulfilled by another avian title: Flappy Bird. Created by Vietnamese developer Dong Nguyen in 2013, it was a simple but brutally difficult game that involved tapping the screen to make a bird flap its wings and fly between pipes. In January, the free game went viral, was downloaded millions of times, reportedly earning Nguyen £29,600 a day from in-game ads.

The pressure of his worldwide hit led Nguyen to remove Flappy Bird from the app stores, but it has been followed by a flock of Flappy Bird "clones" – straight copies, plus games inspired by Nguyen's hit, with different heroes. One based on Miley Cyrus enjoyed its own run at the top of the app store charts. It was a sign that in the mobile world, a hit game can rise from nowhere to global prominence in a matter of days.

4 Free-to-play, but pay to win

Candy Crush Saga, Clash of Clans, Puzzle & Dragons… these are the new kings of mobile play, along with games such as The Simpsons: Tapped Out, The Hobbit and Modern War. What they all have in common is that they are "free to play" games: free to download and play, but making their money from in-app purchases of virtual items and currency. As much as 90% of the money spent on mobile games is now thought to come from in-app purchases; as a guide, research companies IHS and App Annie recently estimated that total mobile game spending reached £9.5bn in 2013.

The argument for free-to-play is that it has made gaming more accessible: people can try a game and pay only if they enjoy it. However, they have plenty of critics: gamers worry that free-to-play games are simply systems designed to prod people into paying.

5 Some people are still buying mobile games

Free-to-play games are increasingly the dominant way to make money in the mobile world: last week, every one of the top 30 grossing iPhone games in the UK were free-to-play, for example. Yet some people are still paying upfront for games on smartphones and tablets. Minecraft is the obvious example: it has sold 21m copies of its mobile edition since 2011, while sticking to a £4.99 price with no in-app purchases.

Meanwhile, Swedish developer Simogo has sold 235,000 copies of a title called Year Walk, and 220,000 of the thriller Device 6, both beautifully crafted games that cost £2.49. This year, an iPhone and iPad game from UK developer ustwo called Monument Valley topped App Store charts around the world, making back its development costs in its first week.

6 Mobile gaming is a mainstream affair

Before iPhone and Android, research regularly showed that around 5% of mobile-phone owners were buying games for their devices. In 2014, it's a very different story: mobile gaming is mainstream. Research company eMarketer estimates that there are currently 20 million mobile gamers in the UK: 51% men and 49% women. Angry Birds was one of the first games to benefit (and, indeed, drive) this change, since it appealed to a wide range of ages and gaming abilities. Candy Crush Saga has pushed that on too: the average bus or train carrying commuters to or from work is now a moving amusement arcade of sweet-swappers.

7 Children and free-to-play is a controversial subject

One of the reasons the growth of Angry Birds stalled in 2013 was that Rovio was relatively slow to jump on the free-to-play bandwagon. Why? The fact that Angry Birds is a popular game (and also brand) for children was a big factor.

The issue of children playing free-to-play games – and sometimes spending their parents' money on virtual items without their knowledge – is hugely sensitive for the games industry.

In 2013, the UK's Office of Fair Trading launched an investigation into exactly this topic, producing a report outlining some of the "misleading commercial practices" that were aimed at "exploiting children's inexperience, vulnerability and credulity" by promoting in-app purchases.

One difficulty is that many of the most popular mobile games – Angry Birds, Candy Crush Saga and Clash of Clans included – are not specifically aimed at children. They just have a lot of under-18 players, and many parents either share their app-store payment passwords or have not changed their settings to prevent unauthorised purchases by their children.

8 Mobile gaming isn't just a threat to console game companies

Nintendo has spent much of the past three years fending off questions from journalists and analysts about whether it has any plans to turn its big gaming brands (from Mario to Pokémon) into mobile games for devices made by other companies.

For now, the company is sticking with its refusal to make such a leap. Rivals Sony and Microsoft are taking a different approach, aiming to capitalise on the mainstream audience for mobile games. Both have launched iPhone/iPad and Android games based on some of their biggest brands, while it's not uncommon to see big new console games also offering companion apps for smartphones and tablets.

9 Mobile gaming is now making its way to TV

Mobile games are already played in the living room: many people are using their smartphones or tablets while watching television. But these games are making their way on to televisions too, as a direct challenge to the consoles. Apple's Apple TV and Google's Chromecast products both provide ways for people to control games on their mobile devices but play them on TV.

Just as interesting, though, is a new generation of "micro-consoles" that connect to television screens to run games. The Android-based Ouya raised £5.1m on crowdfunding site Kickstarter in 2012, although it is unclear how many units it has sold since.

Amazon's new Fire TV set-top box – available only in the US for now – will also be able to download and run mobile-style games, while Apple and Google have both been rumoured to have deeper micro-console ambitions.

10 There's hope still for Angry Birds – including beyond games

If Angry Birds had a less than spectacular 2013, it's because of a range of factors: among them more competition from free-to-play games and Rovio's caution in going free-to-play. But it's still a well-known brand that's about much more than games. Rovio is working on an Angry Birds film, which will be released in 2016, and its Toons.TV network of children's cartoons (including its own) has been notching up views since its launch last year. The company is also making a great deal of money from toys and merchandise – 47% of its revenues in 2013 came from these licensed products rather than games.

And Rovio also has ambitions in education: it has published a range of books and last September launched a scheme called Angry Birds Playground, which is an educational programme covering maths, science, music, language, arts and crafts, physical education and social interaction.

Those birds aren't crashing back to Earth just yet.