Angryverse/Angry Birds Space Assault

Angry Birds Space Assault was a cancelled Angry Birds Space spin-off. It was supposed to be developed by KLab America, a branch of mobile game company "KLab," but it's unknown if Rovio got them on board for this or if this was just a pitch by them.

Gameplay
Apparently this game was supposed to be a 3D Slingshot game where you move your spaceship and attack the choice of your bird in any angle.