"Wow."
That's what I thought as soon as those incredibly lush and detailed backgrounds gleefully reached my eye cones. It's refreshing to see such a craft on Newgrounds, as it borrows heavily from Miyazaki – Princess Mononoke comes to mind, especially the chase scene with that whole theme of darkness/corruption.
There are a few very forgivable mishaps along the way which still don't detract from the experience. I would have loved if you explored the characters a little more, as I feel the second half introduces the various scenes a little too hastily. The surreal atmosphere almost reminds me of Wakfu, also French with a very unique artstyle, I think you guys got that kind of potential at hands. It would be very interesting, I think, to see what you could make of it.