Do not shoot your own humans on the planet! Shoot aliens and rescue the humans as they fall from the dead aliens.
Other than that, kill everything in sight, as quickly as possible, and advance to higher and higher waves.
You will receive a new planet (and a new population of humans to defend) after every four (4) alien attack waves. At this point the points multiplier also advances.
PLBM official website: http://www.plbm.com/.
English 
Comments and reviews
nice game, maybe a bit hard, but it is very addcitive
No comment nor review for this game at the moment.