Verdict:

Nowadays, you’re sent to cinematic jail if you don’t kiss the ground upon which Kurosawa filmed, but while there is no doubt that Seven Samurai is an influential work and features excellent shot composition, it is profoundly flawed, and its style is not for everyone.
The structure of Seven Samurai is of a recognizable type, in which several characters are introduced and then a calamitous event occurs, during which the characters will show how they act under pressure and how they deal with one another.
Normally, this formula requires the first 80% of the runtime to be devoted to the backstory of each character, if that character is going to be present for the main event. This is necessary because you have multiple main characters and you need to understand where their behaviour comes from, as well as the relationships between them, in order to understand and fully appreciate their actions during the final event and also just to be able to tell them all apart, even when their faces are covered in dirt or if the camera cuts to one of them for only a second.
Seven Samurai gives a minimal introduction for most of its characters. Very shortly after seeing this movie, I have completely forgotten 3 out of the 7 samurai, and I would only be able to describe 2 out of the 7, and only briefly. The others were just random faceless dudes.
It is not a spoiler to say that some of the samurai are not going to make it out alive, but it’s hard to care about any of them when the characters are so underdeveloped.
Then we come to the acting, and let’s just say it is a matter of taste. The Japanese have a really expressive line delivery, which is most evident in their anime production. This expressive delivery is aided by the fact that the Japanese language, even when spoken at a conversational speed, can easily be made to sound more forceful than Western languages, with a lot of harsh “zh” and “sh” consonants mushed together for effect. And in addition to that, the movies from that era tended to suffer from overenthusiastic acting in general – a leftover from the theatrical era when it was actually necessary due to the physical distance between the performers and the viewers.
Perhaps as a result of all 3 of these factors, there is a lot of overacting in this film. Toshiro Mifune was given artistic license by the director to improvise physically and Toshiro ran with that license all the way to cartoon-land. I felt a physical need to look away during some of the scenes because it just got too weird to handle.
The reason why Toshiro was given the liberty to go nuts is because the director was worried that the movie would otherwise be too quiet and boring. He was right, because when you remove Toshiro’s character and his contribution to the themes concerning the position and identity of the peasant class, the film is just a story about a few people coming together and then fighting off an attack. It moves slowly, at almost 3 hours long, and not all of the scenes feel necessary, which is ridiculous, when you consider how little time was given to developing the main characters.
The film remains interesting from a cinematographic point of view. The way Kurosawa frames his characters, the way he films fights, the blocking of characters with deep focus, the transitions – all these techniques have influenced future filmmaking and make Kurosawa’s work historically important, but the overwhelmingly positive reactions to Seven Samurai are a testament to Kurosawa’s lasting influence, rather than to the quality of the film itself, and in my opinion, convincing yourself to worship the whole film so unquestionably detracts from its very real qualities and contributions.