Nice arcade game with so many elements to make it enjoyable. The graphics is great, audio is good. I found the gameplay with mouse (even with the delay of the ship speed) more handy than the movement with keyboard.
I liked so much the ability of customizing the gameplay with so many options, you can make the experience fit you ability (or mood), and it's fantastic. This level of customization it's one of the things that, in my opinion, every commercial game should have; having it here for free it's a huge plus for me.
Well done!