The movie is a direct sequel to the events taking place in the animated TV series. If you aren't already familiar with the franchise in some capacity, watching this going in blind would be confusing. I wouldn't recommend that. However, that is unlikely to be the case because the TV series as well as the manga series is wildly popular. In fact, among the most popular franchises of all time already.

To give some context to this review, I want to go ahead & state that I Am A Shounentard. With that being said, I have read & watched a ton of battle shounen series in my time. And, unfortunately, Demon Slayer does not particularly stand out among them. In fact, Demon Slayer is among the most generic, suffering from an over-reliance of genre tropes & gag comedy that makes the series a tonal mess.

One second, they will be fighting for their lives to chop the big bad's head off; the next, the cast of characters will deliver some quirky one-liners. This isn't inherently a bad thing, but, it does undermine the plot elements to some extent as I am never sure when to take Demon Slayer seriously or not.

Regardless, Demon Slayer suffers the most from tropes in its character writing. The main cast of characters, quite frankly, suck. Tanjiro is the more serious mild-natured kind quiet one, Zenitsu is the never serious jokester & pervert, and Inosuke is the always emotional tough guy. These attributes alone pretty much summarize their entire character. And no character development takes place during the movie.

At least the franchise understands its own strengths. That being said, rather than commiting runtime to actual character development, the movie would rather focus on big fight set pieces (which is a good thing). Ultimately, the fights & the animation is what makes Demon Slayer great, nothing else.

Two main fights occur during the runtime of this film. The first of which is a fight between our main cast of three knuckleheads + Rengoku the Flame Hashira vs. Enmu. Enmu is a new big bad introduced during this arc & he has a wide variety of abilities. Foremost of which is a sleep inducement ability, which essentially makes anyone who meets his gaze fall asleep & enter a dream like state. This ability is seemingly overpowered; however, our main cast inevitably manage to combat this broken ability with a variety of methods.

After Enmu's defeat, the next big fight set piece occurs. With Inosuke, Zenitsu, and Tanjiro all recieving injuries after the previous spat, they have to sit this one out. This is one quality where Demon Slayer seems to deviate from the tropes of battle shounen. Plot armor is not that strong in this series, seemingly anyone can die at anytime given the right circumstances.

The next big fight is between Rengoku the Flame Hashira & another newly introduced big bad -- a member of the Upper Moons (for context, this refers to the stronger demons who have received more blood from Muzan). However, this fight is much more serious in nature & significantly better in relation to its predecessor.

This fight is a showdown between the elite of the elite. The animation quality takes it up a notch with amazing flame particle effects emanating from the Flame Hashira himself. & it is just plain epic to put it simply. I think watching this fight would justify the time & monetary cost of watching this movie alone.

The outcome of this battle becomes the catalyst for the next major arc to take place in the Demon Slayer franchise. Both parties become significantly wounded; however, a winner is ultimately declared in the end by proxy of actually surviving. And then, the movie ends.

If I had to summarize my review of this film in simple ratings, I would do it as follows:
1) Characters => 5/10 (they just aren't all that strong)
2) Story => 6/10 (just a simple continuation of the mainline series, nothing new here)
2) Fights => 9/10 (stakes are raised to the highest they have been all series)
3) Animation => 9/10 (suffers from highs and lows; the highs are very very VERY high highs but it can be underwhelming in the less action-y moments of the film in an attempt to save budget i suppose)

If you put these altogether, I think the film is worth watching for people who are fans of shounen, like the mainline series, or just simply want to see what the hype is all about. I would recommend the film as a whole, just not to newcomers of the franchise. It has a very high production value with great animation & fight set pieces that I think most people can derive some enjoyment from.