Here is the full list of all 68 Highway Wars achievements.
Colonized Mars
Colonise another planet
Terraformed Earth back to it's original climate
Terraform the Earth back to it's original climate
Defeated the allied gangs
Defeat the allied gangs
Defeated the alliance of Free Cities
Rescue somebody in need
Escape an ambush
Survive an easy car battle against a Peugeot
Survive a car battle against a Volkswaggen
Defeat a group of bikes and buggies
Get advice from the poor
Take money from bandits
Scavenge some ammunition
Kill the cannibal mutants
Survive an attack by a group of bikers
Jump over a broken bridge with your ATC
Kill all the cannibal mutants
Set out to colonise other worlds
Take command of an army of robots
Take command of a large gang
Kill a vampire
Become a vampire
Convince somebody to release a prisoner
Rescue a prisoner
Defuse the attack on Burgos
Win a car race
Win a fight against a merc
Rescue the engineer
Win a battle
Conquer Najera
Conquer Torrelavega
Overcome an enemy fortification
Ally with those who protect the weak
Make Zamora an ally
Make Burgos an ally
Get married
Race around tornadoes
Protect merchants from bandits
Ally with a former Highway Marshall
Ally with a warlord
Ally with an organised militia
Defeat an organised army
Defeat a gang over rough terrain
Defeat a large gang
Win a fight on top of a high-speed vehicle
Organise the defence of a Free City
Defeat a famous warlord in melee fight
Become a hero of the Free Cities
Become High-Counsellor of the Free Cities