Great illustrations.
I can tell you put a lot of time into this, and you certainly have a lot of skill with storytelling, visuals, and blocking.
Personally, I think the pacing could be quicker, especially in the first half. I didn't feel any connection to the characters, and no interest in what happens to them. I also felt the choice of dialogue was much too wordy and not-believable, and the voice acting severely limited the intended impact of the piece.
Aside from this, there were a few tasty animation sequences, and the illustrations and layouts worked nicely. Focusing on scriptwriting and finding voice talent will kick your future work up quite a few notches, because you've got a lot of other strengths.
And don't listen to the mouth-breather that told you not to use motion tweens. Making them feel natural just takes work, and you're definitely on track. Keep up the good work!