Kingdom of Tjurberg (Version 1)

4 level Single Player / Co-op levels for Serious Sam - Second Encounter - Classic 

You are sent to retrieve an artifact from the ruins of a dwarven kingdom. The story of the defunct kingdom reveals itself to you, as you uncover its dark secrets and the truth about the artifact. Meanwhile new foes appear alongside old foes you never wanted to ever meet again.

(Version 1 uses Advanced Monster Item Classes. Version 2 will come out with the new mod I'm working on.)