As Tom, almost every key just plays C# for me, except P, [, ] and ; I think it was. All the notes worked as Robert. As such, I couldn't really play the call and response mode. Fun idea though, and I really liked the cutout animations.
Which platform are you on? Maybe the Godot builds are a bit hit-or-miss, although I can't understand why it would mess up the input - unless you have an unusual keyboard or system locale? Thanks anyway for giving it a go.
MacOS 10.13.2 (High Sierra). It's an Irish keyboard, so it is still QWERTY and all that, but I could switch to a different layout and try again if you think that would help?
Ehhh.... I tried it again without making any changes and it worked fine! I got one of the eyes to light up!
It's anybody's guess. I developed and tested it on a Macbook with 10.11 so I'm not sure why there would be an input problem. Still, there are probably better games here for you to spend your time on.