Pretty nice game, it is pretty difficult.
It seems maybe the bullets aren't going exactly where the mouse is pointing? Which makes it hard to know exactly where you are shooting, a bullet trail would help with visualizing this some I would think.
Also I essentially kept the zoom out button pressed the whole time as the enemies moved very fast so I had no chance without it pressed.
Good job though, and congrats on getting this made in a week!
(ps please rate my game 😀 )