Good job, really had some gameboy feel with the graphics, sound a music. Controls felt good, the warning icons for where the aliens would fly in is cool, had multiple wave formations and ai. You got a good deal done.
A couple of things, in the web version of the game I couldn't figure out how to get into the Options menu, none of the buttons seemed to work. At the end of the level the game over screen gets cleared too easily if I'm frantically pressing the fire key I don't end up seeing it and then even the game restarts if I am pressing too quickly.
Overall was a fun game to play, thank you for making it.