In a recent discussion on IRC I came up with a constraint on end game that would add a bit of interest. Currently the game ends when players either A. Decide to leave the planet or B. Get bored and start a new colony. This is my idea to put constraints on leaving the planet and thus limit the ability to achieve the actual end of the game.
It is quite simple. If the colony is too nice, and the colonists are too comfortable, each of them when the ship departs ends up with a roll. If more than half of the colonists decide to embark and head back home then you have achieved the end goal. If less than half have decided to leave then you have failed.
**edit**
A further development has brought in the idea of active sabotage by colonists wanting to stay to prevent able bodied people from leaving and reducing the survivability of the colony.
Why would you want to punish players for making a good colony? What purpose does it serve other than ensuring players with grand bases can't win?
Also, that would just ensure that anyone trying to launch the ship would just purposely destroy their base first.