Weird game...
What I found strange about this game was that there didn't seem to be much actual gameplay. It just directly took me to the scene where the action was going on. I went to "Help" but it just told me what the buildings did. I have no idea if this is just a demo or something. I try to click on the buildings, but nothing happens. That being said, I actually did enjoy this because it was pretty much a game that played itself.
I might never figure out how to play it, but I appreciate it. I think the graphics are actually fairly decent and the designs of the enemies are nice. These kind of look more like giant insects than aliens. Then again, seeing as how we've never discovered real aliens, you can never disprove they don't look like that. The sound is good too.