Good work!
That was very well done! I only played the first level (I've got to get back to work myself) but you did an excellent job on everything from the art to the actual game itself. Nice!
Two suggestions. One, that you tone down the sound effects. They got a touch annoying. The screams mostly. Two work on the story a bit more. If it were animated and not "Hey, space aliens are attacking, okay bye" then it might give more incentive to continue instead of quitting early.
Cheers! Keep up the good work!