Fredriksson was very active on the virtual world-building community Metaplace.com. If you don't know what Metaplace was, read this post first. This page was originally meant to embed the actual virtual world Virek Online he built there. Unfortunately, Metaplace is closed as of January 1 2010. Instead, here are vidcaps and screenshots.
Virek Online
This was a light-hearted adventure game built around the musical world of Pettersson & Fredriksson. I wrote all about it's creation right here. It's a long read, but please do have a go. Before Metaplace closed down eternally, I vidcapped an entire runthrough of the game. It's divided in 10 youtube-videos, which are all embedded below. Unfortunately, the sound quality is extremely bad for reasons beyond my control. Just note, that the sound was way,way better then this when the game was played.