Not bad, in fact, very good. Before you fully publish this, I recommend the following:
-A little more detail on enemy ships
-More variety of enemy ships, perhaps a total of 5 different kinds, with bosses
-More kinds of hindrances and power-ups instead of that one bomb that does damage
-Multiple cloud layers, so that you can move the ship up or down a cloud layer. This gives more mobility to enemies, can make for interesting bosses, and makes the game look even further 3D.
If you do this, plus work on the game a bit more, then I'm pretty sure this could even become one of the top games of newgrounds. You gave it a nice looking 3D effect already. Im sure you can do it, and I'd be glad to see this in the front page.