Here is the full list of all 14 Weapon of Choice DX achievements worth 1,000 gamerscore.
Shoot 5 birds.
Rescue someone and get them out of the level.
Kill 10 aliens while hanging by the SPIDER PACK
Rescue every Solus Operative.
Beat all branches
Defeat the Evil Sun.
Beat 'Mountain Village' in under 1 minute, 10 seconds.
Collect all MBG pies.
Use Xerxes to reach a boss without touching the ground.
Use the SMOKE WALK for the maximum time.
Kill 10 enemies with the SPIKE LIFT.
Beat a game branch only killing bosses.
Beat a game branch without activating death-brushing.
Beat all branches in MEGA-WICKED difficulty.