Here is the full list of all 64 King Arthur's Gold achievements.
Take 40 halls
Heal an ally with a burger
Ride in every vehicle
Man them!
Use fire ammo 20 times
Take 10 halls
Blow yourself up as well as the enemy using a bomb
Get 50 stomp kills
Cap 20 flags
Get 5 kills with the drill
Get launched from a catapult 20 times
Get a kill with each class in the same round
Get a bomb kill as an archer or builder
Remain the last player alive in a TDM match
Launch another player from a catapult 20 times
Win 100 matches
Kill the enemy flag carrier 10 times
Steal an enemy's mine
Get killed with a pickaxe 20 times
Get a kill while on fire
Kill someone using a fire arrow
Kill the Princess
Return your team's flag 5 times
Run over an enemy with a vehicle
Get 500 kills
Commit suicide
Cap 5 flags
Get killed with an arrow 20 times
Reach 500 coins at a time
Win 10 matches
Get 50 kills
Eat a flower
Sushi!
Switch teams
Get killed with a sword 20 times
Get a kill on an enemy while dead
Buy something at an enemy shop
Take a nap in a quarters
Design and arrange a shrub
Use chat
Make love, not war
Win a match
Join a modded server
Defuse a mine
Join multiplayer
Get 5000 kills
Kill whole enemy team in TDM (at least 3 players)
Get a kill by launching a boulder from a catapult
Kill a player with a boulder 5 times
Kill an enemy with a tamed shark
Kill 3 people with 1 bomb
Kill 5 enemies with 1 keg
Return your team's flag 20 times
Save the Princess
Complete 10 Challenge mode maps
Ride your tamed bison
Use all animals in game
Use water arrows 20 times
Test the air-speed velocity of a laden chicken
Catapult a shark
Carry 4 burgers in your backpack at a time
Carry all 4 kinds of arrows
Go down with a sinking warboat
Capture 5 warboats