Doesn't sound like this is the way the game was intended to be played. It's not an MMO. The games difficulty scales and progresses depending on how many players are in a world and how many bosses have been beaten. The system works as intended.

Historically, Vikings worked together in clans. Everything about the game is geared toward playing *together* with a friend or two or ten. You can play solo on your own world, but it definitely hasn't been balanced for that (not yet at least).