Well i find this to be, overall, a very pleasing piece to view, regardless of the season

I think that you've used the perfect amount of foreground and background shading and such around the main subject to put it in the forefront of the artwork, allowing it to dominate the entire piece. THe detailing is also very well done. It's things like this that inspire me to strive for greater artistic heights (although being a lefty doesn't help XD )

I especially like the detail on the moon and how it glows with all the little stars in the night sky. Very cool, and overall very well done!

EVILLL!!!! EVILLL!!!
In all honesty there's nothing seriously wrong this piece, it's actually inventive in it's usage of so many elements gathered into one project. The character's design is interesting, the ritual props are nicely placed. All that really annoies me is the following:
1, The tree branches are suspicious in that they're blurred and not fully shaded. 2, the stars in the sky are too apparent, when you look at a night sky, you'll see the stars vanish the closer you get to the horizon. 3, the moon is suffering from the problem of blurr too!
But as I said earlier, the piece isn't bad. I actually like the effort placed into the main focus: the character, and though said character seems off in that it's stiff and not doing much but staring, I know how an artist feels when they've put so much work and time into a certain area of a piece and only then realize the mistake or missing element.

In the end, a clever character design and enviroment concept, the artist just has to slow down and put detail into all the right areas, then again, the artist may have been pressed for time to meet the Halloween deadline, so all's fair from my perspective. CHEERS!!