The controls and aiming need a bit more work here.
At one point, I just sat at a corner and spammed space bar as projectiles fell from the sky. In other words, it wasn't very engaging.
Also, I would avoid having backgrounds that were pulled straight from Google images. I know it's hard to make art, but those images are really out of touch with this. Last thing, have your tutorial show up after the player hits the start button from your game. Having a "How to Play" on your menu would have play testers to skip that.