Here is the full list of all 25 Z achievements. It takes around 5-6 hours to unlock all of the achievements on Windows.
Gattling gun use this against infantry
Desert World conquered
Light Tanks are fast and deadly. Avoid big guns
Jeep are fast moving but easy to kill
Built a Grunt, grab those grenades
10 Territories have been captured
100 Territories captured
Completed a battle without any losses
Single player game completed
Gun Turret: Defence against light armour
Howitzer: Strong defence against all attackers
Build a Psycho, good fighters capable of rapid firing
Build a Tough and launch a deadly rocket attack
Build a Sniper, runs fast and shoots from a long range
Pyros burn and burn some more
Lasers can cut through anything
A.P.C. is a deadly Troop Transport
Medium Tanks are great all purpose vehicle
Heavy Tanks are slow but very powerful
Mobile Missile, why fire one when you can fire three?
Double Missile Launchers are an awesome defence against everything.
Volcanic World conquered
Arctic World conquered
Jungle World conquered
City World conquered