Fun creative game, minor problems.
The game requires really fun strategies in order to make the missles hit and not be hit yourself. That was extremely fun! Thats where you get a 7. :D
Where I took off 3 points is, It was really repetetive with not else much to do but the main concept. It got harder with new enemies, but you still used the same gameplay the whole time.
I've read other reviews and saw that you were working on a sequel, so I won't try to repeat what others have said, when you said the sequel will have much more.
If I could add an idea, i'd like to suggest mouse movement capabilities. Moving with a keyboard was also part of a problem for me, as it limits my movement. I'd like to be able to move freely and faster with the mouse. It would allow for more control.
4/5 for vote.