Obtaining Berserker Achievements
Play a full round lasting at least five minutes as a Berserker
Difficulty: Very Easy
How To: Self-explanatory. Join a game and play as the berserker. It has to be a full round and lasts at least five minutes.
Kill 200 enemies using the big axe
How To: The big axe does a lot of damage, so you'll be able to get kills easily. However, 200 kills is a lot, so it will take some time before you get this achievement.