interesting animation, not so good writing
Visually things worked quite well with your work, the effects were good and the character design was well done, with attention to detail. Animation was fluid, the backgrounds were beautifully designed. The music was quite awesome and the voice acting was convincing, albeit a bit low and hard to listen. What really bothered me was the writing. The story and it's presentation were really odd... I still can't understand why use over half an episode, building and presenting a group off characters that is just going to get killed off and not play any part in the story anymore. The whole first part of the group of thieves could have been cut to just a small scene, and more could have been done to develop the actual plot. After 7 whole scenes, all the information we have is what little was shown in the last 2, and that is really not enough... We know nothing of the world, the setting, the people in it, except that they use little crystals for money, and in the end only one character was really presented to us, Navilyn. I believe that perhaps the opposite would have been better, using 2 scenes for the thieves and the other 5 to forward the plot. When it comes to storytelling the time you have to present your story is limited and therefore must be used wisely. Using this time to present characters and situations that have no relationship whatsoever to the main or secondary plots is just a waste of resources, frames and time.
For your next animation you should keep this in mind and focus on what's needed to actually develop your story and to set the characters and the world they're in.