I can see people watching this and not liking some aspects such as the frantic subtitles and language use, music, or subject matter. Once you get used to these aspects, while navigating a somewhat shaky first act, you can settle in and enjoy the movie for what it is. It is extremely stylistic that focuses on the fun the Kneecap trio is having amidst a serious political backdrop. The more deep you get into the movie, the more it reveals its layers.
The beginning is a bit rough as it is setting up characters rather than the historical aspects of the film's setting. Perhaps of the musical trio of Kneecap were more known, then the beginning could be more engaging, although the real life actors do become interesting once you see where the story is going. We get treated to a movie that trusts its audience to understand how sometimes politics can turn into turmoil by people who take small aggravations into more than expected. You can have fun while making political statements, but the danger that festers around you can sneak up without you fully realizing it. Without realizing it, the fun of the movie, while never letting up, trickles in the serious factors thus making the film more deeper than its first act and therefore becoming really good.
Kneecap could've used a few more rewrites and some more character development. Perhaps there wasn't anything more to develop. Your inner desire to stand up for what you believe in can make your personally connect to our three leads and fill in those shallow aspects of these characters. There are sequences that you may not fully understand due to the focus on style versus wanting to teach the audience a history lesson. I walked away wanting to learn Irish history on my own and appreciate the story that was told.