I think making a review now is perfect due to the 15th anniversary of the movie coming out in theaters, which I happened to see.

Gurren Lagann: Childhood's End (or simply just Gurren-Hen), is a movie version of the first-ish half of the 27-episode original anime of the same name, covering the journey up to the battle of Teppelin, but not actually covering that battle.

Due to it being a recap, the movie is essentially as good as the anime is. And because the anime is one of the best series I can think of, it's a great movie. My only issue is that the movie is a bit too 1:1 with the anime, and a lot of scenes that have serious impact on the story, like Kamina seeing his dead dad, is cut, and some general character building to make the emotional moments match how they feel in the anime. There are some movie exclusive scenes like the intro scene giving Lord Genome a more fleshed out background, even if he's not all that important in this movie, and the movie-exclusive fight with all of the remaining generals (and Viral) in some FFXIV Ultimate-esque, what-if-scenario, mega combining mech. Those scenes look absolutely amazing due to it being, well, made for the big screen.

That being said, some scenes still look really poor. Episode 4, specifically, was guest directed by a friend of one of the Gainax founders. The animation was received so poorly, that people complained, and then found out the guy fought back, saying the comments about the episode were "like putting [his] face next to an anus and breathing deeply." He then left the company. You'd think perhaps they would try to clean up that scene, but no, it just looks really out of place and clearly they reused animation. I mean, it's a recap movie, but come on. I'm not expecting Pixar/Studio Ghibli quality, but it feels a bit lacking compared to other movies in the same medium.

The animation is still amazingly done, regardless. The new scenes are incredibly hype, and the old scenes still hold up as being incredibly thrilling to see in the theater. Unfortunately, I didn't see this one in 4D, but there is a lot of people saying it nearly threw them out of their seats it was so wild. Honestly, if this was any other movie, that would be a complaint, but Gurren Lagann is all about being a thrill ride, so it fits perfectly to see it as such. Just unfortunate that, unless you live in a major city, you probably aren't going to have a convenient trip to the theater. Not even for the 4D version, just the movie in general. Sucks that so few theaters even bother.

Gurren Lagann is an amazing anime, and the movies are no different. Seeing them dubbed finally is a serious treat since they weren't dubbed for the longest time. It helps the dub is actually one of the better dubs in anime. But still, if you were to ask if you should watch the movies in lieu of the anime, I would heavily disagree. The movies are great, but better as a recap of the anime. And if you asked if you should watch this series, I couldn't possibly say yes harder.