definitely a clear "something's wrong" with the hit detection on notes, but I don't think it's as broken as people make it out to be. a lot of the notes are phrased in really bizarre rhythms compared to how you might initially expect them to be based on how parappa actually raps each phrase, which is the big reason I think people struggle with gameplay. I also feel like the game can kinda cheat you at times with certain second/fourth phrases (looking at you, last two lines of cheap cheap and the freestyle section of the final concert).
regardless, the overall Parappa Energy baked within every aspect of this game's design brings me insane amounts of joy and makes this one of the few titles I can fail repeatedly and still have a great time. this silly whatever-animal-he-is has a permanent place in my heart.