Having "canon" as part of marketing turns me off. It feels forced, and in my opinion unnecessary. There is already a wealth of comics exploring the gap between episodes III and IV; they would hopefully make use of that content rather than making a new story.
It sort felt like a Vampire Hunter D story, but looks good to me. Would be good to see more story and character development with all that action, but there's a lot wiki to help the backstory (or rationale for each character's adaptation).
mr_indiff's comments