Necrovision - which, to be honest, we'd forgotten all about - has been effectively banned in Australia, after the local Classification Board deemed it unsuitable for an MA15+ rating.
Those in the know will know that, in Australia, MA15+ is as high as the ratings for video games go, with no legal grounds (yet) to rate a game "adults only" (or, as it would be known here, R18+). So the game hasn't technically been banned, but it may as well have been, since it's the Board's way of politely saying "well, we'd have given this an R18+ if we could, but we can't, so stores aren't allowed to sell it under Australian classification laws".
There's been no explanation from the Classification Board as to why, exactly, the game was knocked back, but being a game about the undead in the First World War, it's most likely go to do with gore and/or violence.
For the record, the game was released earlier this year in Europe on the PC to a decidedly lukewarm reception.
Necrovision banned in Australia [GameSpot]