A new report has found out that the game will be a turn-based strategy RPG. The game is said to be heavily focused on narrative (which could tie-in to the Angry Birds cartoon), and will also feature a "challenging endgame", though it is unclear exactly what that means. The game will allow you to upgrade your characters, weapons, armor, and potions as you progress through. Resources will be found in the game and there will be a crafting system for upgrading gear, but also in-app purchases for speeding up that process. So far, it has also been confirmed that the Red Bird will be the warrior class, and the Yellow Bird will be a Mage, but the other birds are as yet unaccounted for.
Angry Birds Epic will also be free-to-play, but we are fully expecting quite a lot of in-app purchase options. Rovio has been taking that pathway recently as we saw with Angry Birds Go! and its awful free-to-play scheme. We do also know that Rovio is planning a "soft launch" of Epic in Canada, Australia, and New Zealand, which essentially means it needs to test out the in-app store before the full launch, just like it did with Go!.
Supposedly, we should expect Angry Birds Epic to have its soft launch this week, and the full launch at an undisclosed time later this year.