You're likely looking to claim your pre-order bonus in The First Berserker: Khazan if you're just about to start your journey into the game. This bonus includes a unique set of armour that you can't get anywhere else, so it's well worth collecting if you put down your cash in advance. If you really splurged and picked up the deluxe edition, then you'll have even more stuff to claim, including a particularly powerful armour and weapon set.
Sadly, you'll have to progress through the game a little way first before you'll be able to claim these bonuses. Once you do, however, they'll provide a significant benefit in beating bosses and battling through the game.
