Things are on the up for what is arguably the world's biggest publisher of video games. Activision has reported its full-year earnings for 2015, and results show a slight increase in sales, operating income and net income.

Revenues hit $4.6 billion, which is up from the $4.4 billion registered in 2014. Operating income was up from $1.1 billion to $1.3 billion, while net income saw a slight jump from $835 million to $892 million.

You might assume things are rosy at the company, but tucked away in the financial results statement there's a rather worrying note regarding Skylanders and Guitar Hero - two of the publisher's biggest brands and two which will be instantly familiar to Nintendo fans:

Activision Publishing's casual titles, namely Q3 release Skylanders SuperChargers and Q4 release Guitar Hero Live, performed weaker than expected, we believe largely due to greater competition in the toys to life genre and due to the casual audience's shift to mobile devices.

"Greater competition" or course refers to LEGO Dimensions, which, according to MCV, was the big winner in the UK Toys To Life sector, and we're assuming performed just as well in North America. Activision was once the king of this arena, but now has to share it not only with LEGO, but Disney Infinity and Nintendo's best-selling amiibo, too.

Worryingly, Activision also warned that it expected further declines in 2016 for Skylanders and Call of Duty - the former is easy to understand given 2015's figures but the latter is puzzling, as Call of Duty: Black Ops III was one of last year's most commercially successful games.

[via investor.activision.com, gameinformer.com, mcvuk.com]