An amazing, beautiful work; deeply affecting. But I got this for myself, not for kids -- it won't necessarily be accessible to younger viewers.
There are a few potentially disturbing images of just what various immigrants were fleeing. And note that the overall atmosphere/depiction of immigration is of going to a land where everything is strange and changed and slightly mysterious -- the script, the transportation, the food, the animals, the machines, the musical instruments, everything. The viewer him/herself is thereby experiencing what the immigrant experiences: the wonder, confusion, and disorientation of being in this strange new land. That's a powerful experience for the viewer with the context to understand it, but could be just baffling or off-putting for a younger kid. Despite some sad and scary memories of immigrants from various backgrounds, and difficulties and surprises in communicating, the main character finds help from other characters, and does eventually get to send for, and be re-united with, his family, so it has a positive message. If you look through it with a kid, to explain it, I could recommend it for 8+; otherwise, for viewing alone,
depending on a kid's familiarity with immigrant experience, a kid might need to be quite a bit older (12+?) to appreciate it.