This is an all right start. The textures seemed a bit fuzzy on my screen, either as a result of how they were imported or because it was forced to full screen. There's a little lack of variety in the gameplay and I discovered you can get pretty far by just locking your plane to the lower left and holding the fire button, maybe occasionally having to dodge a missile.
The sound design is pretty good though and is a nice touch for giving feedback when you hit or get hit. Good work :)