I think it took me like 3 visits before I finally got it. For some reason i didn't realize I could shoot back so i was just dodging and dodging, so I couldn't unlock any content on my first two attempts.
Other than that, the game is pretty cool. The mechanics are quite easy to grasp, and you actually have to think about how to use the the abilities. And I really appreciate how you have keybinds for both left and right handed controls (WASD vs arrow keys), Which I appreciate because I'm left handed.