Somewhere in my voluminous cellar full of board games, I’ve got a version of this that I bought from Past Times many years ago and which is simply called The Viking Game. Presumably this was because the original name, Hnefatafl, wouldn’t have attracted many customers in a posh UK knick-knack chain, and Centurion Games have taken that thought process to its logical conclusion, giving their iPod version the altogether snappier – and more informative – moniker of Zombwich.
The core of the temporarily-free game (which in the iOS incarnation has been simplified from the orifinal lineup of 24-vs-12 down to a punchy 8-vs-5) is capturing opposing pieces. Each side controls pieces which move like a castle in chess – covering as many squares as they like either horizontally or vertically – and capture an opposing piece by sandwiching it between two of their own side in immediately adjacent squares. But here, some of the pieces are ZOMBIES!!!!!!