Do the following tasks to unlock the following achievements and their alloted GamerScore. There are 12 achievements worth 200 points total.

Mutant - GamerScore 10:
Shoot 5 mutants in one game.

Cooperation - GamerScore 10:
During an Xbox Live Co-Op game get a score of 15,000.

One Wave - GamerScore 10:
Without losing any humans make it to the 2nd wave.

Getting Better - GamerScore 15:
Make it to the 3rd wave.

Fifteen Grand - GamerScore 15:
Obtain a personal score of 15,000.

Competitive - GamerScore 15:
Win 30 Xbox Live versus games.

Nice Catch - GamerScore 15:
Rescue a human with a mid-air catch.

Baiter Bane - GamerScore 20:
During an Xbox Live Co-Op game, kill 5 baiters in any level without using any smart bombs.

Run! - GamerScore 20:
Without shooting, bombing or teleporting survive the first 75 seconds.

Five Waves - GamerScore 20:
Make it to the 5th wave.

Protect All Humans - GamerScore 25:
In the first 3 waves lose no humans.

Twenty-Five Grand - GamerScore 25:
Obtain a personal score of 25,000.