My take on"Innovation" in this context is, how well does the game break the norms of the genre it falls into? If there are common systems or gameplay mechanics, are they identical to other games in this genre, or does it have a unique twist? Does this game push the norms of a genre or create a new genre altogether? I also find this one hard to rate on the games I've rated so you're not alone there. I'm sure there are different ways to interpret "innovation", but this is how I think of it. Hope this helps!