Game looks half done.
There are many small things that could be done to improve the game:
A short summary with statistical information on the unit/structure should appear when you hovor over its button, because even though I read the tutorial, I did not memorise it.
The graphics quality did not preceptibly change when I lowered the quality, which although it sounds good, defeats the purpose of the quality control. The purpose of quality control is to allow a user to sacrifice anti-aliasing effects to increase framerate. I quit simply because the game was running far too slow.
There is also no explanation of the "power" stat that is shown below the price when purchasing a structure. This goes in line with my first suggestion, in that more instruction is needed.