Smart enemies, bosses, missions trench/tunnel layer.

[StinkFist]

Enemies
- Giant bug hive and queen. - competing for resources can tunnel into base.
- zombie hive kidnap people to be eaten - drag victims back to lair - freeze in winter
- nanotech brain infiltrators slowly assimilate your colonist - if undetected, after half of minds taken over they become hostile and forcibly assimilate.
- vampires much like zombies - can't come out during daylight - seasonal enemy hibernates.

Bosses
- large mech with zombie  or nano brain pilot
- giant Ant lion that changes location - think bubba fets death

Spaceship mission
-Actually build a spaceship to orbit the planet which gives bonuses and perks - for interstellar travel you need to build another spaceship in space.

[Katorone]

I like the idea of sending satellites up in orbit actually.  The main question is... what for?