IMO 1st and 3rd well deserved, the 2nd winner is really a curveball by dA, can't believe my 100+ hours work got beaten by that
Yes, what you really mean is to make your art looking more organic?
Interestingly, this is what I have to face on every single artwork of mine, I like that 3D video-game-y feel but trying not to make it looking like a 3D art.
This has a lot to do with blending the subject matter with the background.
I literally 'sculpt' the characters first, then half way through progress I start to really merge and paint everything as one unit.
Btw, what apps do you use? I may assist you in most Photoshop painting tricks I've learnt.