Here is the full list of all 20 Age of Steel: Recharge achievements.
Buy all levels in Survival mode
Earn 100,000 resources
Destroy 1000 enemy units per session in Survival mode
Earn 50,000 resources
Destroy 500 enemy units per session in Survival mode
Buy 7 levels in Survival mode
Buy level in Survival mode
Destroy 100 enemy units per session in Survival mode
Complete campaign
Destroy 100 enemy ships
Complete Act IV
Complete Act III
Earn 10,000 resources
Destroy 100 enemy aircraft units
Complete Act II
Improve your base to the maximum level
Complete Act I
Build a 12 walls at the same time
Destroy 100 enemy ground units
Complete level Hilltown