Here is the full list of all 26 Toy Soldiers HD achievements worth 1,000 gamerscore.
Earned an Overall Rank of General on all Campaign levels
Found all of the Platinum Cubes
Shot down 40 UFOs with your P-51 Mustang
Found all of the Golden Cubes
Found all of the Golden Rockets
Got the Standard Bearer to the Flag Base
Completed any level in Elite mode
Won a Multiplayer Match on every level
Survived until Round 9 on Invasion!
Survived until Round 9 on Siege of Maubeuge
Survived until Round 8 on Creative Defense
Survived until Round 8 on Knights of the Air
Survived until Round 5
Finished Netopyr
Finished The Long Push
Defeated RoboBob
Defeated the K-Wagen
Earned General Rank on any level
Defeated the Rail Gun
Got a 40x blast combo
Defeated the Uber Tank
Defeated the Zeppelin
Defeated the Tsar Tank
Guided a shell to its destination
Completed Level 1
Complete All German Levels and Ration Tickets