If it had some lives and maybe more levels it would be a perfect shooter (I haven't played it enough to know more) I would say graphics wise this game is a 10 on the NES and the play is fast and flicker free on my emulator.
AMAZING for the NES!!! Who ever coded this thing knows a bit about the 6502 thats for sure!
I honestly have to say I am impressed to no end.
Also I would like to add a big Thank You! to who ever made this.