Just watched the trailer... Now I wish I hadn't. That creepy feeling you're talking about is called "uncanny valley." It happens when something like a CG animation or a robot looks lifelike in most ways but the subtle amounts of things that's not right creates this very off-putting feeling. Another hideous CG movie called the Polar Express gave me the same feeling, and unsurprisingly the same studio that produced that pile of garbage also produced this Mars Needs Mom crap. It's like they're deliberately trying to horrify everyone.