Map generation had me start with the nearest non-gasgiant planet 3 places away, and the nearest undefended non-gasgiant planet 4 or 5 spaces away. You might want to update that algorithm because this particular run is more or less dead on arrival
On second though it seems like this game is currently balanced around the faction that can increase its network range with stations. As the colonize-everything faction, after 2 restarts I have yet to be able to colonize a single planet. I have never started with another planet in range and in one of the games I didn't get the 2nd +network range after getting 2 techs in each category, and the nearest planet was further than that. also my tech tree is all gunked up with terraforming options which are useless to me (they should be removed for this faction)
edit: alas, with one more restart i was able to get planets in range and colonize for the first time!
Thanks a lot for playing and the feedback! I think there might be some confusion how colonization works. You can colonize planets outside of your network, but the colonization cost will be equal to the distance from the planet to your network. The UI is doing bad job at visualizing this fact if you don't have enough resources to colonize the planet. This will be fixed in the 0.6.0 update, which contains a redesign of the whole "selected unit" panel.
I'll think about removing the terraforming techs from Yimono. They're not completely useless as terraforming can still be beneficial in order to prevent others colonizing your planets in a dire situation or to change the upkeep of your planets. However it's probably not worth researching them just for this utility. There are more features planned regarding terraforming which will make terraforming more useful for Yimono as well, but they will not be coming in the 0.6.0 update yet.