Story: 6/10
Now, I admit that the story it's kinda original, but nothing that no one could imagine. It's about a guy who one-shots everything with a single punch (pretty obvious from the tittle), and about how he struggles to deal with problems that require more thinking than punching. Now, that sounds pretty cool, not gonna lie, but I think almost anyone could have imagined something similar.
Art: 9/10
This is something I HAVE to congratulate Madhouse for. You know how in a lot of series there are these particular scenes which are extremly more fluent than how it's normally in this series? Yeah? Well, in OPM you'll find them EVERYWHERE. And the fact that they hired internet talents to experiment with the animation is just fantastic. This is probably the biggest pro to this series, in my opinion.
Sound: 8/10
The songs in this series are great, full of hype, fitting for the series and overall fantastic. I didn't found anything that is particularly outstanding, but it does it's job and it does it incredibly.
Characters: 4/10
This is, in my opinion, where the series starts to fall apart. I seriously don't feel any emotion awoken in me when I remember ANY of the characters. As an overall group, it's too simple, plain and without any emotion other than hype. Even in other series that are known for their amazing action scenes, like Tengen Toppa Gurren Lagann, there is some incredibly good character development. In this particular series, the only ones who changed are Doctor Genus (which is a villain that appears in, I think ONE episode) and Genos, because he realizes that he must learn from Saitama to be stronger.
Enjoyment: 7/10
Even though I never yelled, cried or sat in the edge of my seat, I still enjoyed this series very much. I think everyone will find this series entretaining if nothing else.
Overall: 6/10
In my opinion, this anime was nothing more than an action full series, that will be more enjoyable to the kind of people that don't like to think that much or get complicated stories. For me, I did enjoy it, but that's it. It didn't tought me anything, it didn't made me think. Overall, if you're in for good laughs and great fight scenes, I would totally recomend watching this, but for the kind of people who prefer darker, deeper or more complicated plots or groups of characters, I wouldn't judge if you just ignored this series.
And, last statement, in my opinion, this anime is not bad, but it's very overrated.
