Complete the indicated task to unlock the achievement.

Achievement	How to unlock
300 Human Survivors	Completed Stage with at least 300 Human Survivors.
5 Lives	The proud owner of five lives.. nice.
Completed SkillShot	Finished all stages in Skill Shot Mode.
First Blood	Smashed an alien.
First Boss	Destroyed your first alien mothership.
Survived 120 Seconds	Two whole minutes in Survival Mode.
Survived 240 Seconds	Four whole minutes in Survival Mode.
Survived 300 Seconds	Five whole killer minutes in Survival Mode.
Zone 1	Defending Old Blighty.
Zone 2	Defending Moscow.
Zone 3	Defending Tokyo.
Zone 4	Defending Toronto.
Zone 5	Defending Paris.
Zone 6	Defending Paris.
Zone 7	Defending New York.