I've become a fan of Takamiya Satoru ever since I've read La Suite D'amour Du Chat Noir, and noticed that her work does not comprise typical shoujo, feel-good, romance fluff but range into other genres as well, such as the supernatural sometimes. This is one of her stronger points, since this guarantees that no work of hers would ever feel like your typical, 100% hackneyed shoujo manga.
Another bonus point for her is her ever gorgeous style of artwork, which is always a visual feast for the eyes.
For Full Moon Joker, I feel that Takayamiya's artwork is still on its evolutionary phase and not yet as fully developed as compared to her later works. But still, it's cute and shoujo-esque, to put it simply.
The plot is interesting in itself, but since this is done on two chapters only, the execution might be a bit messy but understandable all the same. In fact, the way the author builds up the romantic tension on chapter two makes me go 'squeeeeeeeeeee'.
And I feel it's too short and left off. There was no conclusion, it's just somewhat of a short glimpse into the lives of the characters, and then that's that. A bit unsatisfying, but I've never encountered any work of Takamiya longer than a one-shot, really.
Edit: Takamiya Satoru is actually a guy. Just recently found out. Silly me...