To unlock this achievement, you must simply reach the end of level/wave 5 on each of the 9 Areas.
As
PeaceSquid says above, you do not need to defeat every enemy to complete level/wave. If you are having trouble, allow the time to run out whilst staying alive.
If you want a video demonstration for each level on Hard Difficulty, please see the videos below.
Please either comment below or send me a Personal Message if you have any comments or improvements.