Before anyone can even begin to search for the merits of One Punch Man as an action-parody, the stellar animation and sound immediately grab the viewer's attention. For one, the art and animation stand to impress the viewers at every turn and during every fight. Easily standing out as the strongest overall aspect of One Punch Man, the animation rarely has a subpar moment, allowing the viewers to focus on the anime's storytelling aspects as opposed to becoming distracted by poorly-flowing cuts. Likewise, the sound, although not nearly as stellar as the animation of One Punch Man, does more than enough to hold up under the massive scrutiny that a mediocre soundtrack would receive. The production aspects of One Punch Man, at the very least, make it well-deserving of high praise throughout the fandom.
However, once one moves past the excellent art and sound of One Punch Man, they can begin to focus in on its other story-telling aspects. And, unfortunately, its inability to properly maintain the role of an action-parody detracts significantly from OPM's potential to be the 'greatest anime of all time'.
As a self-proclaimed action-parody of the action genre itself, One Punch Man sets itself up to the standards that any parody must obtain. Mainly, these include poking fun at the standard tropes of the subject, making them comical, and keeping it interesting. And, for a time, One Punch Man did just that. The opening episodes clearly stuck true to its word, in that they were a very passable, somewhat funny, parody of all those standard action/shonen anime that we've all probably seen dozens of times. Saitama's mundane desires to shop at the local supermarket to obtain the sales starkly contrasted the standard villainy of the early-episode antagonists, and his actions as a 'hero just for fun' wiped out all the expectations that one normally comes to expect out of a hero's ambitions.
However, as the series progressed, more and more it left that standard nature of parodies behind. Saitama's mundane wishes flew out the window, and in through the very same window came all the seriousness of any other standard action anime. One Punch Man had, essentially, dumped all of its efforts to become a great action-comedy and had simply morphed into a just an action anime. The villains remained stereotypical caricatures as they had been since the very beginning, but Saitama and his contrast to the norms of standard action tropes had changed. By the last episodes of its run, One Punch Man had ceased being a parody at all, and in fact seemed to have practically given up all attempts to remain a parody. In the course of its runtime, viewers saw One Punch Man change from the good-to-great action-parody that it had started as to a straight-action anime which played all the action tropes as straight as a line. Over time, it fell into the trap of all the action shows that it was a parody of, essentially transforming into the standard hype-fueled action anime that it itself had been conceived to poke fun at.
One Punch Man had the ability to become a great action-parody series. It had all the pieces in place during the first few episodes (even despite a blatant repetition of its main jokes). But then it squandered them.
The hype may have been with One Punch Man, but unfortunately the hype cannot hold up its blatant failures as a parody.
