Very nice artwork, I love that dragon looking creature and how each of the sprites would tie its design to a computerised theme. I like that a scoring system was added, but were levels based around hitting a certain score? If that's the case, I don't think this should be done as score so much as progress through a level, the score would be to bring a person back to try and get it higher either throughout the entire game or a level basis.
The main menu button didn't seem to really work for me and enemies colliding with the player didn't seem to do damage, bullets did the damage.
I did however enjoy playing this, though it did have some challenge to it.