I saw it and thought it very good. The only criticism I would make is that it wasn't "busy" enough in as the beaches seemed almost empty, the Royal Navy ships too small in number (two or three when in reality there was about 40) and not nearly enough aeroplanes.
I understand this was made without CGI to add hordes of men and machines but with 300,000 on the beaches the place should have been much busier and a Luftwaffe that in truth threw all they could at it and which had over a 1000 serviceable planes to be reduced to a pair of Me109's, one Heinkel bomber and three Stukas seemed implausible as did three RAF Spitfires which seemed to take an age to take out the everlasting Heinkel.
https://youtu.be/YOBZcFXn16k?t=218
Hardly saw any Jerries either!