Angry Birds and nonplussed Pigs

I'm addicted to Angry Birds.  I don't know they came up with the concept - but having little birds launch into green pigs and destroying precarious structures just keeps me enraptured week after week.

They had a movie that came out based on the game - but I don't know if I need to see that - I'd rather the interactivity that comes with the game.  And it's weird that the movie versions all have arms and legs...it's like they couldn't just figure it out with what they had originally designed.  But, I guess, it's easier to emote and to interact, not to mention move about if you have limbs.