Yesterday I had someone shot in the liver - instant death as it destroyed it.
This made me think, as getting shot in the liver isn't going to instantly kill you.
The only instant death should be the brain.
I think all other organs should give you maybe a minute or two tops (depending on the organ) to get a transplant operation started.
It just feels a bit pointless to harvest spare organs right now - I'd like to have to keep a spare heart handy for that emergency operation trying to save someone while the other colonists keep the enemy at bay

Ooh and what about resuscitation?
Complete with brain damage if you've been dead too long.
It's just such a fantastic system - one of the best I've seen in any game.
But it can still be better
