Ah, Eyeshield 21, the first sports manga I ever got into when I was a young teen. But how well does the anime hold up to the manga? Its okayish, however, its not without its fair share of issues.
Story- The entirety of the Eyeshield 21 storyline focuses on the Deimon Devil Bats dream of making it to the Christmas Bowl, the championship match between the best high school football teams. The anime does a pretty good job of following the story of the manga. But there are a few changed details here and there, like how Monta is recruited for the Deimon Devil Bats.
However, there is a lot of noticeable filler right before the rematch with the Ojo White Knights. This is usually a pretty sad telltale sign that the anime was catching up to the manga. This leaves around 10 volumes of content that never got animated. Its depressing, considering all the awesome stuff Sena and the other characters were doing beyond the anime. They showed how much of a threat the Dinosaur team was and that match wasn't even shown. But enough about that I suppose.
Animation- The animation, more or less, is decent. The studio Gallop does have some experience doing sport anime, but at the same time I can't help thinking that Eyeshield 21 could have gotten better animation if it was in a better studio. If you're new to anime and haven't seen that many sport anime, you could probably still enjoy it. But sport anime need to have fluid animation to feel impactful in my opinion, cause otherwise what's the point?
Sound- The sound for the anime was done pretty well, from the tackles, passes and running. A lot of the openings and endings are pretty good too, considering the hype for the series too.
Characters- The characters are a huge part of the reason why the series is loved so much. For example, Sena at the beginning of the series wasn't that outgoing and was a gopher for others his age. But as he plays the game, all thanks to Hiruma, he slowly changes from a character who is forced to play the game to someone who doesn't want to runaway and wants to become better at it. That's only the tip of the ice berg when it comes to the character development.
Overall- Eyeshield 21 is a good but also incomplete anime adaption. Personally I think its a good way to get more people interested in the series and quite possibly even get them to read the manga. There are quite a few episodes but for someone looking for good character development, this is a good investment.