Verdict:

In the current anti-authoritarian age, any production about Rome is quick to point out the evils of that oppressive empire. Stories are full of darkness, debauchery and misery. Even if the protagonists are working for the empire, they are thrown around and betrayed by the bloodthirsty and corrupt Roman aristocrats.
So, I was in a way relieved to see a movie that presented Romans, at least some Romans, as US marines, complete with honour, glory, family and all that stuff. But sadly, the honour, glory and family did not result in something more substantial. Not much happens. There is a small battle or two, which was nice, but then it went back to small scale affairs.
It was like spending time watching a day in someone else’s life or the background story of a side-character from another more interesting movie. There is nothing particularly wrong with watching a day in someone else’s life. It’s just that no one was acting in a manner as to convince the viewer that something is at stake, and for that matter, only one or two actors gave a performance of interest. There was no particular artistic spectacle, no edge-of-your-seat plot, nothing to distinguish this movie, except for trying to stick modern military macho bro-ism into a Roman frame.
And that’s the other weird thing about this film: the vibe is not Roman, but American. The Eagle comes off as a US-army war movie with swords, with a few Roman concepts introduced to the story in order to Romanise it.
The movie gets better towards the end, when the plot is temporarily left behind in favour of simpler action and you forget for a moment what era you’re supposed to be in, but then the movie decides to turn up the honour and glory knob again, and the problem is that…guys, choking on stripes and stars just gets a little old, even if you cover those stars and stripes with a Roman suit of armour.
The film is ok. If you are a fan of the Roman era then you have presumably already decided that you will watch this movie. But know that The Eagle not what it appears to be. It is just Black Hawk Down but in a forest with swords. A movie like Coriolanus (2011), despite based on the play by the non-Roman Shakespeare and shot as a modern-day action movie, is far more Roman than The Eagle can ever hope to be.