Here is the full list of all 16 Gunslugs 2 achievements.
Defeat Metal Face
Unlocked Arcade-mode
Escape the wasteland
Survive the jungle
Reach the Himalaya's
Survive the Himalaya's
Reach the planet core
Defeat general P. Hat
Score 1500 in Arcade mode
Score 5000 points in Arcade mode
Score 10.000 points in Arcade mode
You know what you did.. doctor
Completed your first Daily challenge
Completed five Daily Challenges
Completed ten daily challenges
Completed thirty daily challenges