“300: Rise of an Empire” is not quite the movie that “300” was.

Yes, there are a ton of gory, over-the-top battle sequences stylized to be comic book movie-esque, but unlike “300,” “Rise of an Empire” doesn’t feature a solid lead, which considerably hampers the film.

This leaves the movie simply as an action flick for those who enjoy obscene amounts of blood, dismemberment and brutal melee combat. With incredible CGI and truly impressive combat choreography, “Rise of an Empire” succeeds admirably on this front, but those seeking substance should look elsewhere.

Paralleling the story of “300,” “Rise of an Empire” does a surprisingly good job of interweaving Leonidas’ story with the introduction of the character Themistocles and his ragtag fleet of Athenians. Not only are clips from “300” used, but characters reference events before and after Leonidas’ last stand against Xerxes and his Persian army. Additionally, Xerxes’ backstory is explained; his rise to power is directly related to the main villain of “Rise of an Empire,” Artemisia. It is pleasant to see such continuity in a sequel, as this lends unexpected credibility to the franchise itself.

“Rise of an Empire” contains the same amount of over-the-top action as its predecessor. This time, however, almost all combat takes place on water, with massive fleets of Athenian and Persian ships clashing on the Greek coast. Led by the ruthless Artemisia, played ably by Eva Green, the Persians must destroy a smaller, motley group of Athenian farmers-turned-soldiers, led by Themistocles, played less ably by Sullivan Stapleton. While Green is convincingly brutal, sexy and merciless, Stapleton is consistently wooden throughout the movie.

Themistocles does not display emotion well, whether watching his friend die or watching his fleet get destroyed. Likewise, “Game of Thrones’” Lena Headey puts in a substandard performance as Queen Gorgo, reprising her “300” role. This acting inconsistency means “Rise of an Empire” lacks emotional depth. While surely not the movie’s focus, this lack of an effective cast severely diminishes audience investment, devolving “Rise of an Empire” into nothing else but an excellent action movie.

Visually, “Rise of an Empire” will melt your eyes. Outstanding detail is ubiquitous, whether it is a thousand splintered ship hulls ramming each other, the fiery, chaotic battle zone in the movie’s second act, or the hundreds of individual wood chips dislodged as an arrow strikes a shield. The change from “300’s” ground combat to “Rise of an Empire’s” water-based action doesn’t feel forced or fake, as every wave is rendered brilliantly and each ship is realistically detailed. Obviously, “Rise of an Empire” is stylized, meaning combat is exaggerated; this is where excellent CGI is imperative. Slow-motion sequences and complex camera rigging is masterfully executed, making each combat sequence exciting and satisfying.

As a parallel story, “Rise of an Empire” carries the story set forth in “300” quite well. Injecting references and clips from Leonidas’s plot into “Rise of an Empire’s” events, there is a welcomed sense of continuity. However, “Rise of an Empire” lacks an equally impressive cast as its predecessor, which undoubtedly hurts the film’s emotional impact.

There is really no line or event that will be remembered as fondly as Leonidas’s “This is Sparta!” moment, but nevertheless, “Rise of an Empire” stands on its own two feet as an action movie. Thanks to amazing CGI and exhilarating battle sequences, fans of “300” will find plenty to love in “Rise of an Empire.”

Grade: B-