Good Stuff!
this was a pretty decent flash game but it was a little too simple. even if simplicity was ur intention, there were a few spots u could've improved on. here's sum tip:
have a variety of enemies. even if they are simply a different color, it breaks up some of the dissapointment of seeing the same exact enemy each time. have bosses too. they dont have to be hard, but try and make them innovative. upgrades are always nice too, such as dual firepower or homing missles or sumthing, and in this game, an invincibility upgrade would probably be the best.
anyway this was still a very decent game and what impressed me most was the game's physics. the plane didnt immediately halt when u pressed a different directional button, it gradually changed directions which added a pleasant dimension to the gameplay. overall: good stuff and i think a sequel would be appreciated.