fitgirl has it. gameplay feels kinda dated, but with some nice additions. Looks pretty good, and the horde engine is cool, lots of baddies to shoot. Unless the pvp and online coop modes are amazing, I can't imagine it being worth 60$, but for the price of free, i'm digging it.
There is no tyranid perspective anywhere in Warhammer because that would gave people too much info about the tyranids and toppled the carefully maintained alienness of them. Even when you can play Tyranid campaigns like in Battlefleet Gothic 2, the story is from other PoV.