Here is the full list of all 13 Viking Rage achievements.
Kill 500 Enemies!
Kill 250 Enemies with the Bow
Kill 100 Enemies while in Rage
Kill 250 Enemies!
Kill 100 Enemies with the Bow
Survive a Level with less than 5% Health left
Kill 100 Enemies!
Teleport 500 Times!
Loose a Level without Killing Enemies!
Fire an Axe with a Bow!
You completed the Tutorial!
Kill the Mountainboss only using Axes
Kill 50 Enemies through Explosive Barrels or other Traps