Our team have used unity3d to build our bubble shooting game from the scratches. Currently, we are interested in buying the graphics asset from Chupamobile to use for our game. Check this http://www.chupamobile.com/ui-graphic-asset/very-angry-birds-bubbles-game-gui-assets-10420 However, that graphics asset is similar to Angry Birds (but different). Anyone knows if we use that graphics asset for my bubble shooting games, is it legal? Thanks so much for all responses!