Really nice ! It works pretty well.
I had the same problem as Shweep, i didn't really distinguished the small trees as food at first x)
I was kinda sad that the ennemies don't do anything apart from going directly to my guards, maybe permit the ennemies to kill the worker would add a little more difficulty.
It is a really nice working prototype of an RTS that works, so good job on this one !! :)