The Good

Jujutsu Kaisen 0 covers many of the checkboxes for a great movie.

The plot is solid and engaging. Not outstanding, but no major issues. I'm definitely invested in the main character, possibly more than Itadori. It's an absolute treat to see the side characters from the main TV show in action again, and I mean it, because nearly all of them reappear in the movie. The animation is fantastic, and cursed energy is always cool to see. There is plenty of action to let the animation shine throughout the movie. The music is great and enhances the experience. Not in a way that I'll be downloading the soundtrack to my playlist, but it worked perfectly to increase the impact each scene had.

Something I really like is that some side characters receive more attention, and as a result you find out more about their past and personality that wasn't told in the main show.

The Bad

It's easier to write about what I would have wanted instead of what I already got.

Although the movie is entirely built upon the main character's backstory, it is painfully neglected. In fact, if you've seen it, the movie's trailer doesn't recap his backstory - it's pretty much what you get when you watch the actual movie. If you haven't seen the trailer yet, I wouldn't recommend doing so. It cheapens the already weak backstory by spoiling it ahead of time. Towards the end of the movie I actually felt somewhat emotional - so if they had just put in an extra 10 minutes towards the backstory, which wouldn't hurt at all for a 1 hour 45 minute film, it could have been phenomenal.

On top of this, I wish the flashbacks to the backstory were presented in partially unique and overlapping pieces - not a repeat of the same scene each time. I can understand why it was done, because it works just fine under TV show pacing, just not in a movie where the last time I've seen the flashback is at most 10 minutes ago. This also leads into the next point.

My other gripe is that Jujutsu Kaisen 0 doesn't utilize much of the advantages of a movie format. It doesn't feel like a movie - it feels like the back-to-back episodes of a slightly short TV show arc. To be completely honest I can't exactly explain at the moment why it feels this way, but I suspect part of the reason is the pacing, and a weaker central theme. A recent example of another shounen action movie that, in my opinion, was able to successfully adapt to a movie format and utilize its advantages, would be Demon Slayer the Movie: Mugen Train.

Conclusion

All in all, Jujutsu Kaisen 0 is a great experience, and highly recommended. The quality and content is on par with the main show, so if you liked that, you'll love the movie too. If you haven't seen the main show yet, I would recommend watching it first, as the movie leaves out quite a few details and assumes you already understand concepts explained in the show. If you haven't seen any of the trailers yet, keep it that way. Finally, there's a post-credits scene that apparently sets up season 2 and 3, don't miss it!