I really liked the presentation here: just fiddling with Light and seeing the hidden messages brought joy to me! It's neatly implemented - though, to be fair, ends up being more of a story gimmick than a curious mechanic as it ends up being straightforward.
Not sure if I missed something, but I really wanted some resolution in the end. The game gave me choices, but then the story abruptly ends, giving me just the satisfaction of the choices I've made - in this context I would expect some form of ending, maybe even a small puzzle element where you need to "keep one course of action within all choices" and get rewarded for that.