How many people are working on this game?
Have you made other multiplayer games before?
Just me and first time trying to make a multiplayer game of this scale
Well, you should try making small games first (by small games, i don't mean 2D or 'small' games).Try singleplayer games first. Ask other devs/programmers to play your game. If they're interested or wanna add more to the game , get their help too. constantly keep searching for what's new/trending in survival games. the main thing is your audience. Don't perform in an empty hall. Advertise your game as much as possible. that's all i gotta say. :D
This might help you > http://wannabe.urustar.net/