Very Good
It's awesome, but there are a few things I don't like about it. For one, the enemies never change; they just get stronger, faster, and shoot more often. There's no variety as to what they can do; you have the regular ships and the boss ship. That's it. Some variety would be nice; I liked the sudden change when the first boss battle came, and I wish there were more interesting things like that, instead of all the bosses being the same.
The other problem I have is that there's no auto-fire button. It was something like the 26th wave when my clicking-finger was going numb, and it was either quit, die, or lose a finger. This game, despite its unoriginality in places, is addicting, so I kept going until I died again and didn't feel like continuing.
The last problem I have is the enemy missiles. There's nothing you can do to take them down, and you just have to keep flying until they blow themselves up. I personally think that's just not a good a idea.
All in all, still an EXCELLENT game, but it just has a lot of little faults along the line.