Here is the full list of all 12 Imperi II achievements.
Get 1,000,000 score
Get 2,000,000 score
Acquire 1,000,000 Grain
Acquire 1,000,000 Gold
Acquire 30,000 Land
Have 500 Clerics at once
Command a 50,000 troop army
Reach 40 years old
Reach 50 years old
Reach 60 years old
Reach 250,000 population census
Defeat the Imperi