Well, mission programming hasn't started yet - but the ideas have been worked out, so i've started looking around for someone to map mission 4 for me (im not a good mapper).
The outline:
It's going to be a unit-only mission. Objective is to "raid" an enemy base. Player will come in with attack vehicles and some trucks and/or other vehicles - i'll keep that a secret!
Anyway: the map should be large enough to fit a big base containing some 3 or 4 mining routes, 2 CC's a couple of factories (VF and SF), agridomes, residences, std and adv labs (about 3 or 4 in total) and some other buildings like nursery, university and a garage. I'll need some space for walls, tubes and GPs ! I'll leave it up to you, but i think 64x64 should already be big enough, but i might need twice that size; either in height or width..doesn't matter.
Most of the base should be on open terrain (orange soil), surrounded by hills on all sides, with several passes (about 5 or 6) through them, at least 3~4 tiles wide. terrain may contain some debris - even around the base area, as long it's "passable" so tubes could be built over them.
Of course the area around those hills is normal rock - there will be NO lava-rock (darkgrey) in this map.
Hope this explains it well!