Great level. Very nice challenge.
The only gripe I have is that the defensive trees seemed a bit strong. You had to have quite a force (or get lucky in my case) in order to take a planet with at least 1 D-tree. But I guess that made the initial part of the game more interesting.
The other thing I noticed was kind of a bug. I haven't seen it in other levels, otherwise I'd post it in the Bugs forum.
Not sure if you can see it clearly, but this planet (controlled by light/lime green) just bought a Defensive tree and it hasn't even sprouted yet, however it has released several defensive seeds right away. I had this happen multiple times on this level. It happened with me and the AI controlled planets.
Anyways, great game. I'm working on my own level and hope to upload it soon
Edit: Nevermind. Found a similar post in the bug formus related to the same thing I saw. Oh well.