Brilliant
Using Classic Powerups And Enemies To Make a similar game borders on plagiarism, but the game you have produced is almost flawless. It involves the classic enemies, but other features like the buying screen for powerups and addons is a good concept for the game.
Although the game draws concepts from Geometry Wars it is still very worthy of a high score for compiling it in Flash. The graphics are well drawn and the trailing effects add to the game's charm. It deserves an overall 8/10. Perhaps in a future release you could include a mute button to stop the sounds, and maybe add more creative enemies and a larger playing screen.