How to enjoy this game to its fullest: Upgrade 1st gun to max... play insane difficulty... hold mouse button on the left side of the screen. Close window cause every level will be the same.
This game has potential to be great but it lacks difficulty. At first i was like wow these guys really zoom in but soon as i had spread on my gun it wasn't a problem any more. I think that it would help out a lot if the regular gun didn't stop the enemies in their tracks when they got shot.
All clear for take off!