I think it’s a nice touch to make such a simple game mechanic richer with a little introduction, with an enticing goal (learning the secret fact about the character if we reach the last level), and having a credits song at the end, along with an introduction and ending bit.
I don’t know if the mechanic ties with the story - I would like to see it tie with the story somehow. But I think as a puzzle it’s nice and pleasing in itself. It’d also be richer with a real voice over, which I think you could try finding someone to do it.
I would make the sound for clicking the arrows keys less high-piched as it was a little itsy bitsy screeching in comparison with the TTS speech.
Nice one, simple but effective and pleasing to play.