Angry Birds 2, nominally the first official sequel to the original mobile titan, has launched on mobile app stores.

Actually the thirteenth title in the series, Angry Birds 2 hews close to its predecessors' bird-launching, pig-annihilating gameplay, with a few tweaks.

Players can now choose which birds they fire at their enemies; levels have multiple stages, bosses, and improved animations; and various new spells and abilities are scattered throughout.

Most notably, microtransactions are built into the foundation of the game in the modern, frustrating model of limiting repeat playthroughs (in the case of failure, for example) unless players pay up.

Developer Rovio is likely banking on Angry Birds 2, given its marquee franchise's flagging popularity, its recent layoff of 16% of its workers, and its co-founder and CEO's departure from the company.

Angry Birds 2 is available now on the iOS and Android app stores.