Friggen hard controls
I started getting used to them sort of but then i died.
You seriously need to consider changing them. Change to just left and right. Both doing a full rotation. It will be 100x easier. Also the game is a little plain. Try adding some things that can help you more? Add a nice background and such.
I got to part 9 wave 6 before i died. Good concept, i just don't think you executed it to well. However, i'll vote 4 and give you an 8.
Hope you polish this game up a bit more =].