I wasn't sure what to do at first, had to do it more than once to figure it out. Even got stuck on the windows that pop up before the actual game, didn't realize I needed to click on the "user" response one. Also I'm not sure if I could see all of the user one, it may have gotten clipped off the bottom of the screen.
Once I realized how to do everything properly and what to do, it was a better experience. I got to the wave where they start going backwards.