This could easily be one of the best Dutch movies made so far. It is not only an amazing accomplishment because of the spectacular naval battles and special effects, but also because it manages to explain all of the historical context. And on top of that, it not only manages to tell De Ruyter's story, but also that of other important historical characters, such as Charles II, Willem III, Johan De Witt, and several others.
The movie struggles occasionally to fit all of De Ruyter's career in just one movie. And especially the first half of the movie suffers from misplaced patriotism that feels almost un-Dutch, with a lot of slow motion close ups of waving Dutch flags, and long winded speeches about freedom and liberty. It struggles with its dialog, and especially at the start it often indulges too much in spouting exposition, and in trying to remind the audience of the time period.
But those minor issues aside, this is a great film. It even takes some risks by showing Wilhelm III's blatant taste for boys over girls, and by showing the gruesome betrayal of the brothers De Witt. All of this is historically accurate, so that can't really be considered a spoiler to anyone who has bothered to read a bit of history.
The movie has a great soundtrack, and beautiful costumes, while using a lot of real locations (which have been made to look period-accurate with a little help of some CGI). At times the ships clearly look computer generated, but all of that can be forgiven because of the beautiful camera work, and an almost American-style of cinematography. This movie does not look Dutch. It looks like a Hollywood movie. And I think that makes it a lot more accessible to foreign audiences.
I recommend it.