I just rewatched it after 12 years since the first time I saw it, and I found that it wasn't as fun as when I watched it as a kid. However, I still rate it highly in of animation quality and the score by Yuki Kajiura, which really enhances the emotional atmosphere of the anime.
As for the story, both arcs feel a bit slow. The first arc, Aincrad, starts off interesting, but there are many filler episodes that don’t contribute much to character development. I was expecting more action and intensity from this arc, especially since it's the opening arc.
The second arc, Fairy Dance, which is noticeably lighter than the first, has a much clearer goal and focus. The story moves straight toward its objective. While the game system isn’t as engaging as Aincrad, the plot doesn’t stray too far off course.
Overall, I still think it’s an anime that can be casually enjoyed in 2025. If I want to relive some nostalgia, I could rewatch it. The music and score are well done, but as for the enjoyment of the storyline, I was a little disappointed.