I am a big history buff, but I have never read the original Heike Monogatari. Thus, unlike some other reviewers, I cannot comment on the differences between the original work and the anime. I can only comment on the anime. I will also try to keep spoilers light.

Overall, the anime is pretty good. The best part about it is how it depicts the impact of the events that unfold on the lives of different characters. The battles were also interesting, especially the final Battle of Dan-no-Ura. Some characters were portrayed as more interesting than others, with Shigemori being a standout. The pathos of the story was pretty good.

Also, I applaud the anime's makers for covering historical subjects, which are seldom portrayed in anime. Thus, despite all its flaws, I am get to at least have some show for Heike Monogatari for exposure of that historical saga. Just hopefully, people would look further into the characters and events portrayed in the show.

However, the technical aspects of the show were rather lousy:

• The artwork was very simplistic, borderline poor in some scenes.

• Many of the characters look alike. For example, Shigemori looked just like his brother Shigehira. Taira No Kiyomori looked a lot like Emperor Go-Shirakawa (both characters were depicted as somewhat obese bald men, the key difference being that Kiyomori liked to wear red while the Emperor tended to wear white).

• The opening music was good. The ending music was interesting, but being a more modern and edgy piece, seemed out of place.

• I agree with people who say the story was too rushed. Some scenes were barely touched upon and the events of several years could happen in the span of half an episode. Also, people who are not well-versed with Japanese history would likely get lost. I had to look up characters and events on Wikipedia myself numerous times.

• Perhaps the issue is also present in the original work, I don't know, but it was not entirely clear why people hated the Taira. Kiyomori was ambitious, sure, but I would imagine many leaders back then to be. He was also vengeful, but again, so were many leaders. Historically, the real issues arose from bad blood as a result of the Hogen and Heiji Rebellions (which the Taira crushed), but those events were hardly covered at all. So you come across a character like Minamoto No Yoshinaka and be like, "Why does he hate the Taira again?"

Also, I question some of the characterizations in the show. For example, Minamoto No Yoritomo was depicted as a wimpy and indecisive man, but history depicts him more as a conniving strategist. Minamoto No Yoshinaka was presented as a Tarzan-like character, which while somewhat amusing, seemed rather out of place in a more serious show like this one. I highly doubt the historical Yoshinaka swung across trees to fight enemies (and if he did, he must be the most badass warlord in history /s).

The show's epilogue was also weak/non-existent. The show seemed more interested in lamenting or commemorating the lost (which holds consistent with its general strength of pathos), but it did not clearly show what happened with the victors. Were they benevolent and wise rulers? Did they usher in a golden age for Japan or did they become embroiled in further conflicts? Did the defeated factions have any remnants who rebelled or eventually integrated back into the society and politics? Those types of topics would be interesting to cover as an epilogue, but they were not covered.