Here is the full list of all 10 Pixel Strike 3D achievements worth 1,000 gamerscore.
Win 5 Free For All matches
Win 10 Capture The Flag matches
Reach Level 10
Reach Level 30
Reach Level 60
Reach 1st Prestige
Create a custom character skin
Reach 100,000 Coins
Reach 15th Prestige
Collect the 5th consecutive Daily Reward