My tip for people playing this game is to raise the mic's sensibility (Windows' "Sound" settings > Input > Device properties > Levels). I love the game, but I noticed that I was having to hum very loud for it to notice my voice, and I noticed the same thing happening to other players, from their gameplay videos. Maybe it would be nice to add some in-game settings to change that?
I personally bumped mine with +20.0 dB, and my second playthrough was much, much easier.
Awesome game, really. Shame it's short. Any plans for creating a longer version (of course, not a "pay-what-you-want" version)?