As things progress, we learn that there's been a secret war going on behind the scenes of World War II. Psychic, spiritual warfare is conducted by secret military divisions. Of course, the Nazis have found the most evil spirit to recruit to their side: a long dead, ruthless baron that has a huge grudge against Russia. Nadya and her squadmates are the only hope against this spirit threat, but that's the problem. The rest of her squad of psychic warriors in training are also quite dead. To remedy this, she's hooked into a huge, iron lung-like machine (nicely fitting into the time period style) that will allow her to cross over to the realm of the dead in order to recruit her team back for one last mission.
Towards the end, First Squad seems to drift back into the land of comfortable anime standbys. It feels like Nadya's squadmates play the roles of a kind of Power Ranger superhero team. It's strange, because it's almost as if the movie is just reintroducing something that the audience is supposed to be familiar with, but the audience has no idea where it came from. It also seems kind of strange that psychic battles are fought with flamethrowers and bullets, but hey, there's that Sucker Punch element again.
The animation is fluid, and very lovely. Character design is pretty original, especially with all the varied styles of the other members of Nadya's squad. Although much of the movie is spent in snowy, bleary countryside, there's more than enough variety and detail to keep things interesting.
It's too bad this seems to be a one movie deal. There's a bit of a loose end at the end of the show, which does point to a possible sequel. You just kinda feel like you were led on a roller-coaster ride that let off right in the middle of the track. It feels like the world was just beginning to take shape before the movie ended. Either way, First Squad is a refreshing diversion from the norm in anime. It's at least worth a look.