Wow, this is certainly an interesting one. I personally haven't listened to many of Sibelius's pieces. But I like this interpretation. Every movement is something completely different yet it makes sense. I'm not too sure how to describe it.
I really love the sudden change that you made in 1:58. Despite the guitar SoundFont not being the best (At least I'm assuming it's a guitar since it says in the tags. It honestly sounds more like a traditional European guitar or a traditional Japanese plucked instrument like a koto).
The percussion at 2:36 caught me by surprise. The beat/rhythm was not what I was suspecting. It was a nice change. 3:30 is another example of this. 5:40, I really like how you sped up the drum kick to every quaver (or crotchets if you have a very fast tempo). It really made that section feel like the climax of the piece. 0:41 Call me crazy but I feel like a slower beat in this section would have been nice. Almost like a friendly post-intro warm-up to the song. I also feel like (And I know this is probably a very stereotypical drum beat.) a snare would have been more impactful than a clash.
I don't really have much to say about the melodies since I actually liked them all.
Once again I'm just going to say it. I really like how much the song contrasts as you *move* through different movements. great examples of this would be 00:39, 2:21, 2:54, etc. I think this may have been one of your best pieces yet. The more I listen to it, the more I enjoy it. You did a really good job with this one. Keep it up!