I think that what you achieved on such a complex game is what makes the review great; i'm pretty sure you could have done a 30min review easily, but your 12min are enough to give the core +/- of the game. 12min might even be too much for some games :)
I also agree to some extend with
Hey Please on the scoring part, I much prefer when a review gives a "final word" or a quick sentence on a game instead of a figure (would a 9.4 game be really not as good as a 9.7 one ?). But this is only a small detail and I think you are on a really good track for the future.