Can someone explain what all the different planet policies and terraforming does? I can't seem to find details about how it all works and what everything does.
I believe terraforming mostly affects the slaves you get as tribute/demand, like high gravity will result in more muscular slaves.
Policies affect obedience, tax rate, prosperity, or population. Some affect multiple.
Hourglass - i think this means useless citizens are tossed into it, can get you a random event whereby you are visiting the planet and iirc;
spare the person sent to it
spare and enslave
do nothing