Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Perseverant Award (50 points): Complete all Bonus Missions.
Bronze Sharpshooter (50 points): Earn all Bronze Medals in Action Zone.
Silver Sharpshooter (75 points): Earn all Silver Medals in Action Zone.
Gold Sharpshooter (100 points): Earn all Gold Medals in Action Zone.
Platinum Sharpshooter (200 points): Earn all Platinum Medals in Action Zone.
Experienced Hunter (50 points): Complete the Career Mode on Normal.
Pro Hunter Award (100 points): Complete the Career Mode on Difficult.
Apiphobia (20 points): Destroy at least 10 Bee Hives playing Career Mode.
Completionist (60 points): Complete the game 100% on Normal.
Skilled Hunter Award (20 points): Use all Power-Ups at least once.
Snakes on a Plain (20 points): Take down at least 15 Poisonous Snakes playing Career Mode.
Rabid Completionist (120 points): Complete the game 100% on Difficult.

Additionally, there are nine secret achievements:

You're Grrrreat! (15 points): Completed all objectives in India while playing Career Mode.
Mane Event (15 points): Completed all objectives in Tanzania while playing Career Mode.
Nice shooting, eh? (15 points): Completed all objectives in British Columbia while playing Career Mode.
Buffalowned (15 points): Completed all objectives in Congo while playing Career Mode.
Bear Necessities (15 points): Completed all objectives in Thailand while playing Career Mode.
Rumble in the Jungle (15 points): Completed all objectives in Ecuador while playing Career Mode.
Bear-ing Straight (15 points): Completed all objectives in Alaska while playing Career Mode.
A Spot of Luck (15 points): Completed all objectives in Namibia while playing Career Mode.
Bear shoots you! (15 points): Completed all objectives in Russia while playing Career Mode.