I thought this game worked pretty well with its simplicity. I mean, I was amazed at how much harder it got after awhile. If nothing else, I'm glad I got to play a game like that. I do, however, think there could have been variety with the enemies. Then again, the enemy that was different was completely invincible.
I think I went from 120,000 to 0 in seconds. That's rough. I found the music to be fairly good. I really do like the sound effect when you fire. It's a nice, sci-fi sound.