With Angry Birds 2 unlikely to be released anytime soon, if ever, Rovio Mobile has made a cunning move with the surprise release of Angry Birds Halloween.

It's not the Halloween theme that's the really cunning move however; plenty of other games from Doodle Jump to Pocket Devil have pulled that particular trick.

Going solo

No. The development of Angry Birds Halloween - a new, standalone app for iPhone and an HD one for iPad - has enabled Rovio to self publish the game under its own steam.

Its breakout hit - now though to have been downloaded over 20 million times in terms of paid and free versions - was published by UK outfit Chillingo, which gets a cut of all sales.

However, with Angry Birds now the world's largest mobile gaming brand, Rovio is keen to spread its own wings, and keep all the cash. 

It also self published the Android version of the game. It's believed that Chillingo retains the rights to the PSP Minis version.

Check the small print

In this respect, the release is also interesting as rumours are swirling around about the possible acquisition of Chillingo by EA Mobile, or perhaps another company.

Of course, that would make sense, in terms of Chillingo's proven ability to deliver a regular volume of hit iOS games.

But the price will be the most significant element of any such deal, especially in terms of the value and extent of publishing rights Chillingo has over sequels and additional platforms for the iPhone games it's released.