Guren-Hen is predominantly material ripped right from the TV series without so much as an airbrush, and while there are a couple of changes there’s absolutely nothing major plotwise. Simon lives a boring life in the underground village of Jeeha, where his main job day in and day out is to dig tunnels. His close friend Kamina, however, longs to bust out of their oppressive existence and reach the surface world where open skies and adventure await! While digging, he finds a miniature drill along with an eye to some giant face. Being made fun of for being weird and enjoying digging, Kamina cheers him up and aims to have his Gurren-dan (Gurren Brigade) drill through the ceiling of the underground village to get to the surface, but is stopped by the village Chief.
I won’t get into the meat and potatoes of it all, mainly because there is a lot of ground to cover. Gurren-Lagann’s garishly colourful visual style sets it apart from so many of its mecha peers. However, aside from the entirely new, explosively excessive ending and a handful of other sequences that have been touched up quite late in the film, Guren-Hen never feels any more cinematic than its predecessor on the small screen.
If you expected a complete visual overhaul for the screen and full-blown remake with numerous plot tweaks like the new Evangelion films, well, that’s not what Guren-Hen is. The only reason why this film is getting recommended is because I hadn’t seen the series beforehand. If you have seen the series, I can’t honestly recommend you sit through this one. Simon takes Yoko and Kamina to the miniature gunmen he found and Simon is asked to pilot it. Somehow managing to activate it, they go out into battle. Kamina names Simon’s gunman Lagann and with some encouragement, Simon manages to defeat the enemy gunmen and make it up to the surface. This is where the movie really takes off.
A few changes in the movie was that Kamina’s dad being mentioned/shown was completely deleted, while they rushed a lot of the irrelevant stuff. A lot of the scenes that would take an episode or two were shortened a lot and for the most part, the movie itself was just the TV version in film format, with the change of the general battles and deaths. The only real sacrifice is some material involving secondary characters, regrettable but somewhat understandable. I think this is as about a good translation as one could expect. If you haven’t seen this film or don’t mind rewatching most of the series again in movie form, you’ll likely be reasonably satisfied with this movie. If you want anything more you simply won’t get it.