During the transport to the Island, at least two of the photos seen on the plane's wall behind Inara are actually "actresses" in this movie: Sam Sexton, who plays one of the women on the Island, and Cali Danger, the film's lead.
In the final battle with the soldiers, the women are victorious in an Epic Sword Fight. Although some soldiers lay on the ground apparently dead, none of their clothing is cut and there is not a drop of blood.
Although the tribes of the Amazon historically have pierced their noses and lips in such a way as to create the appearance of having whiskers, they did not very often have a single belly button piercing.
The Mercenaries use machetes and knives because of the Electromagnetic properties of the island interfering with their weapons. In the opening sequence of the film, however, Inara's father had no problem using a pistol to shoot, and kill, the other soldier while on that same island.