I recall seeing a thread on a possible new mode called build mode. I attempted to make one with what Hedgewars already offers. In it you:

-the first three turns you can only build making your own unique defenses
-mainly a two player mode(right now) with two islands to begin your fortresses on
-Default like weapons once you get started

Hopes(I don't know code or script so I don't believe I can do this stuff)(if you can you are welcome to help):

-be able to build then place your guys or place a guy a turn and be able to build on that turn
-have a new mud/terrain weapon(similar to flamethrower)(or mudballs that leave terrain where they hit)
-make it so only the construction is replenished each turn not all the weapons

Possibilities:

-you could make it so both teams are on opposite sides or you could allow them to be on either island when placing teams

Screenshots will be up soon.

I will post a demo on the demos page once I have one.