This was an interesting experience
When playing this game I went through what I thought was all branches but I was left curious about the whole glitch/migraine/dream subplot of the game that apparently had no clear pay off. So I decided to look through the files where I realized you were using persistent variables to keep progress across runs to unlock a secret ending. I'm very glad I found it, it was really cool to feel like I had found something unique and helped immensely with making this game feel like a complete experience.
But I worry that this element of this game will go unseen. Since the secret choice only appears after you think you've seen everything, many players will probably miss it. Even a small hint after a bad ending would help more people reach the conclusion of your game
overall I'd say there's a lot of creativity here, and I'd gladly play more from this team