Unoriginal
It wasn't a terrible attempt for your first game, I mean I've seen much worse, but it wasn't good either. The concept has been done time and time again and your rendition wasn't a very good one. It was way too simple, all you did was haphazardly shoot the same enemys while dodging their never varying attacks. On the plus side, I did enjoy the bosses and graphics were pretty interesting, but that was about the only real enjoyment I got out of this game. But all is not lost, I'm sure if made another game (and put in much more effort!) you could do a much better job. Just try to be original and and add real substance to your game. Do you really just want to create something that's been done so many times before?