Basically SAVING PRIVATE RYAN for the Brits.
First half is great. Then it starts to become unbelievable with sequences involving (I'm trying to avoid "spoiler alerts") a German pilot, river crossing, abandoned baby, singing in the woods (better done in OH WHAT A LOVELY WAR), lengthy water escapades and a mumbling Benedict Cumberbatch who may or may not be on message - I couldn't tell.
The final credits reveal the script is inspired by conversations with Mendes's grandfather - which would explain the episodic and sometimes fragmented narrative.
But the performances, production design, camera work and direction are ace.