Some of the reviewers elsewhere were clearly not even born in 1969 and have treated this as a "fillum". It's much more than that, even as seemingly nostalgia for Branagh's childhood.
Notably most of it was not filmed in Belfast - if you could imagine what the sight of extras in the uniforms of the RUC and the British Army could have encouraged.
It usefully mixes up the viewpoints of children and the adults around them, as The Troubles fire up. Initially, the entry of the British Army into NI was welcomed, as protecting the Catholics from the B-Specials of the RUC. One street becomes the motif for what followed - burning out the "Carfillics" only encouraged the random shootings later on the doorsteps of both faiths.
The film gently teases out the decisions of his parents to move out to England, for a better life and keep the children safe. As I suspect, so many made the same decisions later.
The images in the film of helicopters overhead, barbed wire barricades and armoured cars on the streets were extremely realistic. You had to be there, at the time. I was.