An animated movie about troubled teens, and quite possibly for them as well, because it’s so very like them: alternately sweet and scary, tender and violent, dense and scattered, and oh yes, childlike and adult. (It sure ain’t for kiddies; the people are cartoony animals — dog cops, trash-picker mice, etc. — but the island setting is a million miles from Zootopia, tonally and visually speaking.) The great grimy engine of the world grinds along, oiled by the blood of the guilty and innocent alike, just waiting to discover and be discovered by a certain sort of unhappy mousie, one who is physically comfortable but emotionally bereft. (She’s especially so now that her beloved, the titular Birdboy, has found a new best friend in powdered form.) What she learns is that there are no happy endings — nobody gets out alive, and there’s plenty of pain before we give up the ghost — but there remains the possibility of love. Very grownup. The experience is frustrating at times: the film should be either narrower in scope or longer in length to accommodate its many storylines. But writer and co-director Alberto Vázquez effectively relies on range of imagination and intensity of feeling to keep the eyeball staring and the heart bleeding. (2017) — Matthew Lickona