Currently in my developing game world, I use a human type player character, it lives on a dirt world with a few trees and whatnot...  I have no real problems with it, it is what it is.  However it creates a LOT of work for a solo developer/designer/3dmodeler...etc.. Organic modeling for YEARS!! 

So..  I'm considering a change of venues and player character types.  Something like modular robots on an abandoned garbage world, kind of change.  This or something like this could make for a lot more almost-code-only solutions to npc and maybe even player character objects.  Interchangeable parts with different functionality, that kind of thing..

Anyhow, the questions, do people have a harder time getting into games that don't have a Human player character?  Is it enough that the characters perform human like behaviors, interact, needs, wants, desires.. etc? 

I've been searching a bit and most articles I can find with anything about the topic reference in some way a majority preference for players choosing a Human race in games where there are other options, could it be inferred that some majority of players will gravitate away from games that don't feature actual human characters at all?

The game mechanics I'm working with are fairly generic as yet (in order of dev priority) multi-player online, sandbox, crafting, racing, adventure, fps, pvp.. 

I'm a systems guy, so basically I'm building a multi-player gaming environment + (insert story here), and I'm curious if there's any precedence for NOT using robots as your player character/All characters? 

Do people just prefer pretty faces?

Aha!  Yes!  

That's kinda what I was hoping/thinking, and it wasn't any in-depth research, I think one was talking WoW and the other was from a while back about Guild Wars 2..  I obviously didn't get very far into researching before being struck with the question. I'm sure those cases had/have as much, or more to do with mechanics/story elements/etc. as esthetics... 

I'm really just trying to pair down my modeling work load without sacrificing "necessary" design elements.  The AI will work about the same either way, but I don't have to disguise that it's AI if everything is actually AI..  And it allows me a super-highway sized path to bring some "programming/hacking" game elements into the mix.  Which is something that's been nagging at my brain stem since starting this project.

I think I can make it work.  Thanks for the vivid example!

Non-standard player characters don't have as wide of an appeal, but, because of their rarity, they have devoted fanbases.
As far as "getting into" characters, as long as the player has the means to readily figure out what he can do with his character and how to do it, he won't complain.

Thanks @Lendrigan Games!  I'm full speed ahead programming a world full of junked robots!  No more worries about modeling a bunch of lame human clothes and bleh-cetera.. lol