this is a character i modeled last Saturday. i modeled, textured, rigged and made basic animations in one single sit down(i was in my zone) anyway she’s made for a video game, which i will hopefully be making soon. the darker line below her eyes is her nose, not her mouth. its a bit hard to tell in this render due to the brightness and lack of shadows. i would appreciate any critique or advice!
Only the one render isn’t a whole lot to go on. You might want to post renders from different angles and with better lighting to give everyone a better impression of what you have.
Personally, I’m really not quite liking the eyes. I feel uncomfortable not seeing them both focused, and the absence of the whites around the iris is also very noticeable.
The feet also look odd to me. I’m not sure what style you’re going for, and if you have something very specific in mind or not, but traditionally chibi style characters use the form of the leg and just add the hint of a foot on the end of it (depending upon how complex they are).
//Edit: Sorry, just noticed that what I thought were modeled on feet turned out to actually be only the reflection of your character on the floor. My bad. Looked like white shoes. 
So again, if you have something more specific in mind, you might want to post another render with better lighting and a few more appropriate angles.
As far as the nose, I’d try to add something to it to make it more clear that that is what it’s supposed to be. Maybe a mole, or a ring. I’m not sure, but again, given that we’re used to seeing that line as representing the mouth in the traditional way, it’s too easy to confuse it with the way it is.
Hope that helps! Really cool concept by the way. I think just focus generally on making it look more easy to connect with, i.e. easily recognizable human features on the face that help your character to communicate what you need it to.