Solanin is an example of such a flaw. Whilst it does have some focus on music and the passage of time, the former is a minor focus for the first half and the latter doesn't start to appear until halfway through. Even when both these topics become integral to the story, neither is executed in a way that stands out compared to other series.
On the topic of music, this story focus shows how many parts of the series are limited by its medium. A lot of impact is taken away from a story with a focus on music when there is no way of hearing it, or even a way for music buffs to imagine the songs being sung when not even as much as the musical notes are present.
Speaking of not making the most of the medium, it's time to talk about the art. As far as the backgrounds and character designs go, they're fine, though not outstanding. One damaging factor that did stand out to me, however, is how many black spaces are used for monologues. Stylistic or not, it seems wasteful to limit the visual element of a visual medium so much.
That said, the series would have been a lot better had it been condensed into an anime original movie with some of the filler chapters removed.
As far as characters go, they serve their purpose, but are in no way any different from what you'd get in any typical slice of life or romcom series, nevermind stand outs for manga in general; and the time wasted focusing on the mediocre support cast causes the story to meander and weaken the series overall when the series would have far more worth as a conceptual piece than a character one. The main character at least has some development from events that transpire later in the series, though as far as female characters growing as people from a loss in their life has been done in far more interesting and fleshed out way through both Misato from Neon Genesis Evangelion or Kanna from 20th Century Boys.
Overall, the only reason Solanin seems to have gotten any sort of praise is for its relatability, though that element means little when every other factor of it is a mediocrity. I can at least give praise to the mangaka executing things competently for what they wished to accomplish, though that premise was just more of the same. If wanting to see interesting ways of how to make a focused story with slice of life elements, watch the anime Planetes, Haibane Renmei or The Tatami Galaxy; or far better, look outside of the anime/manga medium and watch The Sopranos. For Solanin, however, I can provide no sort of recommendation.
