Here is the full list of all 20 History Legends of War: Patton (NA) achievements worth 1,000 gamerscore.
Game completed (Campaign Mode)
Fourth operation completed without casualties (Campaign Mode)
5 heroic victories achieved (Campaign Mode)
All types of units unlocked (Campaign Mode)
Third operation completed (Campaign Mode)
Third Army completed (Campaign Mode)
200 German units destroyed (Campaign Mode)
Max out any of Patton's Skills (Campaign Mode)
Second operation completed (Campaign Mode)
First aircraft recruited (Campaign Mode)
100 German units destroyed (Campaign Mode)
First operation completed (Campaign Mode)
First bazooka recruited (Campaign Mode)
50 German units destroyed (Campaign Mode)
First upgrade made (Campaign Mode)
First tank recruited (Campaign Mode)
First mission completed (Campaign Mode)
Tutorial completed
Kill 15 German soldiers with knife (Campaign Mode)
Get 10 heroic victories (Campaign Mode)