For me, it's hard to attach a rating onto a genuine oddity like B&C. In my many years of movie viewing, the flick remains a true one-of-a-kind. I don't know how the producers did it, but the birds manage a whole array of intricate tricks and self-control. The amazing results don't look like animation. Yet, I wonder whether ordinary looking birds can truly be trained for sliding down wires or standing on their heads. I wish IMDB had more info on this key matter.
Anyway, the story is about young feathered lovers Bill and Coo and their bird town Chirpendale. Much of the charm and amusement comes from converting people-talk into birdie-talk, like Chirpendale. Most screen time is taken up with the Starling Circus where the acrobats do their people-like stuff. Then too, viewers never know what trick is coming next. Intruding now and again, however, is the looming menace of the big crow, but instead of a black moustache to twirl, he struts around in domineering fashion. So it's good guy Bill against bad guy Crow. It seems some Hollywood cliches never change even in bird land.
Anyway, I can see today's kids being entertained by the oddity just as my generation was many years ago. But viewing it again as a geezer, I think many adults could also happily catch a novelty that somehow escaped the Hollywood assembly line. Meanwhile, I'm off to happily double the goodies in my patio birdfeeder.