These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Adaptation Displacement: The movie is undoubtedly more well known than the original manga. In part because the manga had a really screwed up release. Marvel Comics bought the rights to translate it/bring it over to America when the movie was released in the US in 1989 and but Katsuhiro Otomo's decision to redraw the last 1/6th of the manga led to the US version seeing a massive delay in the publication of the last eight issues and by the time the last issue came out in 1995, the series was out of print as well as the trade paperbacks, of which only 10 of the proposed 13 volumes ever saw the light of day. It was not until Dark Horse Comics got the rights to the series in 2000 that the manga received wide release, in terms of availability.
Animation Age Ghetto: Despite that the movie was originally rated PG-13 in the U.S. (With the 2001 redub earning an "R" rating!) you can still find stores that put this in the "family" shelf. Other stores at least put it in the dedicated "Anime" section, leaving it to the person browsing the shelf to at least use their own discretion when searching for stuff to show their children.
The movie is sometimes cited as the one thing that first proved there was potential for animation beyond the ghetto.
Gateway Series: Towards anime. Steven Spielberg had claimed the movie to be Unmarketable in the U.S. due to the Animation Age Ghetto. This movie was rated PG-13 when the first dub hit the screens...in the 80s, this actually stood out a bit.
Hilarious in Hindsight: The story is in a backdrop of the 2020 Neo-Tokyo Olympics, and Akira was apparently below the unfinished Olympic stadium. Guess what happened at September 9, 2013? Tokyo has been selected as the host of the next Olympics in 2020.
Hype Backlash: Inevitable given the amount of praise it still gets.
They Changed It, Now It Sucks: Many fans of the manga have this complaint because because the film tries to cram the first half of the manga into a single movie (many for first two acts it has plotlines following three to four characters at a time) and doesn't use the second half due to a divergence in plot.
They Wasted a Perfectly Good Character: Kaori is Tetsuo's girlfriend, probably one of the few people who really understood/cared for him and she ends getting just a handful of lines, beaten up and then kinda killed towards the end of the film.