Took me a while to figure out how to colonize a planet. A better description of the controls would be:
- Left-click on a planet to select it.
- To colonize: left-click on a colonized, source planet and right-click on the target planet when a line between them appears to transfer 1 population. Right-click repeatedly to transfer multiple populations.
A minor grievance I have is that some planets share the same orbit which isn't true to real life.