Stargunner much?
You could mention that you took the idea from old game called Stargunner. It is shorten 1st episode's level 2 of Stargunner judging from the boss. Dino and roarrring is kind of funny so plus for that original idea. But to be honest I 100 times more prefer Stargunner- looks better, controls are better and music is better (and the game is like 14 years old. )
http://www.youtube.com/watch?v=71wNGc hneAQ&feature=related