Edit: Wow, didn't expect this to get featured, Thanks very much!
Edit 2: The key bug should be gone now, thanks to geco-deco12 for finding the cause of the glitch.
I have a time-lapse of me making the game here if you're interested in that kind of stuff: http://www.youtube.com/wa tch?v=0SNfvh8IxrE (You gotta take away the space after the a in watch. )
Z - shoot
Enter - Select continue if on main menu or advance any other screen.
Directional Buttons - move
Use the mouse to click menu buttons
This was made for Ludum Dare 26 in under 48 hours. (To be honest I only really got about 12 hours worth of work done because of other things needing done.) I didn't get much time to balance the difficulty so I'm afraid it's pretty hard. It's pretty short though with only 6 levels so it shouldn't take too long to beat.
I used the following tools: