Love the Characters, especially the left one.
While i really love the characters, and even recommended it for the art portal because of the charaters, i've only given 3 stars because i believe you need to work a little more on the background. The pathway or whatever they're standing on seems to fall out of the rest of the style.
I suggest adding a thin outline or blue it out instead.
TLDR: Good characters, but you need to work on the backgrounds some more to compliment the characters better :)