[Bird Wife]

Hi – I contacted Rovio recently and there’s an update:

I have now contacted our developers, and apparently, the song in Mighty League is the remix of Darude – Sandstorm, which is used for a different achievement. The Birdday sticker says “Listen through the BirdDay song when it is available!” so according to our information, it should be available to complete around Birdday (December 11th). I hope that helps.

In case of any other inquiry, please do not hesitate to contact us again. Have a nice day!

Best regards,

Steve
Rovio Support Team