Diminutive worlds are more likely to be rocky, and lapped by oceans and atmospheres. In the vernacular of 'Star Trek,' these would be M-class planets: life-friendly oases where biology could begin and bumpy-faced Klingons might exist.
In general, when moviemakers talk to scientists, they usually see them as a resource to solve particular technical problems or script problems for them. So, something like: what sort of weaponry would aliens be able to wield?
Judging by informal observation, most young Americans burn up their spare time buffing their emotional IQ and self-esteem with social media and non-stop texting. That's great for eye-thumb coordination, but what about the satisfaction of actually making something?