Unusually, Human Head have chosen to make Valhalla a multiplayer-only pack, not even including any kind of offline bot support for solo players. If we had just shipped a single player add-on in the traditional style, our potential market would have been pretty small. The potential market for Halls of Valhalla is far bigger, since anyone can buy it. We'll just have to see if that experiment works. Human Head apparently aren't too worried by this though.
Most expansions typically do poorly, very few do well.
Rune is something new - not the same old blast 'em up you've been playing for years. It is a game focused on a different type of gameplay that offers different challenges and a different way to play. In the Aztec society, the team that lost got their heads cut off. We thought, let's cut out the middle man and make a game that allowed you to use limbs and heads as the method of scoring. Human Head are also aiming to make the game more user-friendly for the mod community with the release of a new set of tools and the latest version of RuneEd, along with the launch of a Rune editing website to help people make the most of them.