This action flick could've been rated PG13 easily if it wasn't for one slightly bloody throat slit scene, in overal most of the martial art scenes are bloodless. And don't expect any gore.
One man gets shot in the head by an alien, a slightly bloody spot can be seen.
A man gets stabbed in the face by an alien, his body gets thrown on the floor. The alien then crushes his head with it's foot, only a small puddle of blood can be seen (no gore).
A man gets impaled with a sword, and a woman gets impaled on spikes. The only thing you see is a bit of blood running out of the woman's mouth (nothing graphic).
There are a few scenes with gunfire at the beginning of the movie but no one gets hit.
The alien gets slashed a few times, you only see a bit of blue blood.