This is a really nicely made game! Difficulty level is about right for a short experience like this, definitely a challenge for the final boss. Graphics and sound are great.
My only complaint is I found the mouse pointing to be unusual and difficult to keep track of because I was mostly looking at the bottom third of the screen micro-dodging bullets. I kept having to catch a break in the bullets just so I could look elsewhere to find my pointer. Maybe having a bigger pointer graphic, like a big red crosshair or something, would have made it easier to spot.
But hey, a minor gripe, I still played the whole thing and enjoyed it a great deal. Good job!