The undead battle system

First topic message reminder :

To be honest I think the current undead fighting is really boring, at some time I would like to put a few weeks on making it really interesting. I have a bunch of directions I think we could go with this:

Order vs Chaos?
Should the battle be nicely ordered in wave after wave (like gear3 horde) or should they just pop in random more like Minecraft?

Intergration vs different game mode?
If I keep the battle part of the creation, like now, people can fight zombies in their nice castles they make. Or the other hand, making a separate survival mode would allow me to limit the resources and make it a lot more challenging. Maybe you would have to collect coins or materials to be able to build. The monsters could also be more destructive more explosions and all that.

limited building? Do u mean were only have certain blocks or not that much time to build because the waves or constanly spawning or...?