The Linux port currently does not support steam workshop, and as the mac port made by the same developers has not received workshop support despite having been out for several years, it is unlikely that it ever will. Though there are unofficial workarounds to get the mods working.
Policies are used as a tool to gain a variety of customizations that benefit ones society. There is a branching tree of policies that will allow the user to pick certain aspects that will suit them best such as adding law or religion to ones society which will give gains in certain aspects.
Civilization V has a great combat system that feels very tactical over previous versions as there is no stacking of troops, but with the new hexagonal grid players can surround enemies as well as allow for better tactics when planning attacks.
Frozen Synapse has deep tactical possibilities. You have to take into account your environment (there's even destructible terrain), strengths and weaknesses of each squad member, position and viewing angles of every man on the field while developing a coherent plan of action by setting waypoin...