Unique in the annals of animated films, Watership Down is a serious, even grim tale that many will find relentless and depressing and others will find poetic and moving. It doesn't pull any punches. Death -- violent, disturbing death -- is ever present, portrayed in a manner that is astonishingly honest for a cartoon. As a result, it is that rare animated film that really aims for a mature audience, despite its superficial funny animal trappings. It has a brilliant opening, most likely created by UPA veteran John Hubley, which in a primitive and simplistic style relates a creation myth as told by rabbits. The style changes thereafter, with beautiful watercolor backgrounds and a more natural approach to character animation. Unfortunately, the animation suffers somewhat from this point, becoming a bit sloppy, although it continues to portray the characters' movements as realistically as possible. The character designs themselves are rather too similar, with the result that it is sometimes difficult to tell the various rabbits apart. The story is also sometimes told in too-broad strokes, leaving those unfamiliar with the novel confused as to exactly what has happened and, more importantly, why. However, these flaws are redeemed by some unforgettable sequences, including a chilling segment detailing the destruction of the rabbits' warren and a devastatingly sad end sequence in which the Black Rabbit of Death gently takes one of the heroes away with it. Voiced by a fine cast, with stellar work from John Hurt and Richard Briers, Watership Down is an imperfect film with some of the most powerful moments ever created for the genre.
~ Craig Butler, All Movie Guide