Doesn't look that interesting, but I'll try it out.
As of now, Dead Frontier is still the best zombie-apocalypse MMORPG there is. Fast-paced or slow-paced gameplay depending if you're massacring zombies or looting (respectively), customize-able characters, 100+ weapons to choose from, and bosses that actually take hundreds of rounds to kill. (right, Banoi the Butcher?)
No interiors of buildings as of now, but it will be re-implemented in the 3D version. And so will barricading them and turning them to personal outposts. Once they have been, no other game of the same genre will be able to fuck with it now.