Here is the full list of all 22 Original War achievements.
Stepped into the EON
Complete American campaign on any difficulty
Complete Russian campaign on any difficulty
In any mission have more Apemen in your service than people
Drop a siberite bomb
Join the Alliance
Before entering the EON attack your own men
Spare Kurt
Collect over a 1000 crates
Stay with Americans
Employ the mercenaries
Kill Gorky
Kill Macmillan
Don't enter the EON
Prevent the Russians from building their second base
Make Lisa and Joan betray Americans
Make Legion join your forces
Hand over the Arabs building mortarmen barracks for you to UPF
Let the Arab build the mortarmen barracks but don't hand over Heike to them afterwards
Stay with Russians
Stay with Platonov
Complete Tsaritsyn's quiz with all correct answers