Bjorn describes the game as "a similar premise" to Wurm Online, in that everything in the world is player-made with the exception of natural objects. It's not just a bland Wurm-clone, however. The world of Salem is a little darker, with a harsh justice system, witchcraft, and otherworldly creatures like Hide-Behinds -- creepy predators that hide behind things as they stalk you.
Bjorn explains part of the justice system, discussing what happens when a player kills another (or commits any crime, for that matter): "He leaves a little scent behind, called the Stench of Crime, a kind of clue. Those clues can be used to track the crime; I get up this little window here, where I can choose to track the perpetrator, the claim of the perpetrator, or the item that was stolen. [...] And if the crime is serious enough [...] I can also use this clue to summon the character into the game, if he is offline."
There's much more, so head to Rock, Paper, Shotgun for the full interview!