SAN DIEGO - For the forthcoming film adaptation of "Ender's Game," some much depends on scale. Space travel is quite big, but its soldiers and stars are still quite small. For its young actors Asa Butterfield (Ender) and Hailee Steinfeld (Petra): they'll just be thrilled to see more than a green screen.

"The visual effects guys are awesome," Butterfield told HitFix during San Diego Comic-Con today.

The pair -- among others  on set -- were transformed into soldiers by going to boot camp, and space travelers by hitting up space camp. It was suring that time they learned to operate as a functioning (if sometimes dysfunctional) military family unit.

"It all happened really uickly but it sort of worked in a way -- although we're a family unit -- we're put in a position where we don't know who to trust or who not to trust," Steinfeld said.

But she and Butterfield appear to trust each other now, as she chided her co-star for his lack of nail art. Check out our zoom-in on her 10 works of art above, plus listen to Butterfield's description of Ben Kingsley, who also worked alongside him in "Hugo."

Be sure to check out the Ender's Game Arcade, featured on the grounds near the San Diego Convention Center during the con. The film hits theaters on Nov. 1.