Good game.
Graphics: I gave you a 7 because although your graphics aren't the best we at newgrounds have ever had, they still clump together nicely and don't look as if 2,3,4,5,6,7 different animators did them.
Style: Nice, liked the rocket and it's handling. I like how you had to aim with the cannon at first, was pretty sweet.
Sound: Alright music, various choices - all of it lacking in adrenaline though.
Violence: A healthy 5 seeing how the most violent thing is exploading and/or blowing up a building. I only gave it a 5 because i hope some poor child's mom is out there looking at her kids screen saying "This inspires terroism" just so i can see her in my dream and hit her...alot.
Interactivity: Start button, music changer, game controls, exit button. All interactive and well deserving a 10.
Humour: Well, it wasen't that funny - it wasn't supposed to be - but exploading things made me laugh and so did the fact i couldn't do some of it and it took me while.
Overall: A nice, healthy 8. It was good, but not fantastic. Enjoyable, but not incredable. Hard, but not a mission. Good game, keep it up.
Advice: Fix the glitch(that i am about to specifie) and look more into it. Maybe make it 3D. Also, the cliffs you smash into - couldn't a rocket just sore above them?
Glitch: 3rd level which looks like a broken down city. If you turn your cannon to the brown thing and shoot, the smart bomb just sits there and doesn't expload, even if you press space.