Well, this is your basic epic war film that doesn't dare and try to explain why the war in question actually happened. In this case, it's because freedom and patriot we want british evil revenge blaargh BOOM! So, yeah, not much depth to that particular part of the story.
On the other hand, the action scenes are great, and the acting is quite nice as well. The cinematography and sound are quite good, and the character development is above average. Finally, the time period is quite an interesting one, so it's nice to see on film. This is all countered by a slightly overlong running time, though.
In a sentence:
Worth watching for the great battle scenes and the pretty entertaining and decent plot. On the other hand, be prepared for a movie that's a bit too long, and almost entirely inaccurate.