I like this piece. I like the coloring (the sky whith the clouds interact so well with the ground) and I really like your cartoonstyle kangaroo. However, the skintone of the female character blend to much with the trees. I haven't seen the serie myself but the color of her clothes kinda break the smoothness of the artwork (I don't know if I make some sence here but I hope you understand what I mean..). Maybe the shadow on the ground should have more clear edge to it as it might become too smooth.
I do think this is great artwork and I would love to see more like this :)
(I hope you don't mind me giving this feedback as you asked for some feedback in the forum..)