I will straight this movie is not good it is basically a recap of infected and spread, does not service the show well. So watch those first if you plan to watch this.
Now there is a Unique story is in that is Ulith story is of course a character from infected and spread. Is worth watching for that. If they did less recap and more of Ulith story focus I think I would have enjoyed it more, but what I got was still ok.
I don't wanna say anymore but that is what you get with the movie so now you know what you are getting.