It basically comes down to it that this is a lesser version of the hit movie "300", in just about every regard.
The movie tries to stand on its own but at the same time still desperately attempts to tie in to the events of the first movie as well. It's neither a sequel or prequel really, since the movie for most part is set around the same time and battle of the first movie. It's more of a spin off but it doesn't work out that well, mostly due to the simple fact that this movie is inferior to "300", in just about every way imaginable and the references to the first movie often feel forced and completely needless.
Sullivan Stapleton ain't no Gerard Butler and Noam Murro ain't no Zack Snyder. But it's not just that; it's also the story and the writing itself. Main thing that made "300" great and a real 'man's movie' was its main premise of having an handful of Spartans versus- and making a stand against, an enormous and extremely diverse army. It was thrilling, heroic and quite often spectacular as well. All of that is missing from this movie. It's a far more generic movie with its story, that basically involves one group of Greek soldiers against a group of Persian soldiers. Nothing too special or engaging really. Nothing ever works out as anything too original or thrilling. The movie is lacking some truly great and outstanding moments in it, as well as some likable characters and uplifting dialog.
Even the action really isn't anything too memorable. It's never anything truly spectacular or that well shot and even though the movie basically involves a full scale war, it just never feels as such. It's probably because the movie mostly sticks to just the Sullivan Stapleton and Eva Green characters and basically just about everything that happens in this movie involves one- or in some cases, both of the characters. Even Xerxes gets reduced to a sidekick and henchman in this movie, which was one of the things I really didn't like about the movie. He was a great, powerful character in the first movie but in this one he gets toned down, in favor of the Eva Green character, who they try to portray as the bigger and more powerful, ruthless villain. She is not a bad villain but I definitely would have preferred Xerxes over her. Well, maybe not in every way but you know what I mean.
Thing I also thought was weird about this movie is that it's for most part taking place during the events of the first movie but yet, we still have to sit through the same build up and exposition again. In some ways, it's telling the exact same story again, only told from a different perspective. This of course still could have worked out well but it's however never anything all that interesting or seemingly relevant, so it mostly works out as something that only needlessly slows the movie down.
Visually it's an OK enough movie. Again, compared to the first movie it really isn't anything too impressive or new and like I said, director Noam Murro really ain't no Zack Snyder but it's a decent enough Zack Snyder-style action flick, with extensive slow-motion scenes, heavy use of CGI, exaggerated violence and fancy camera filters. It's still a movie that entertains good enough but I just can't call it a very good movie as well.
Maybe only a good movie if you haven't seen the first one yet. For everybody else; there is absolutely no reason why you should watch this inferior rehash.