The music is good and I like the concept, but the execution needs work.

The game is just really short, there's no gameplay to speak of (even just some basic platforming would make a difference), and you should find a better way of conveying the story than just a text dump at the very end. Even just splitting the text you already have and spreading it across different screens would make it that much more impactful.

I think this might be better as a movie, at least how it is right now. Alternatively, have a bit more emphasis on the nothing part, like having a Legond of Zelda-esque animation when opening the boxes that says "You get nothing." Additionally, having a little challenge for these boxes might make the futility thing more impactful.
As it stands, this is a rather shallow game. Of course, if your game's about nothing, then it's hard for it to be something, isn't it?

Edit after update: You listened to what I said, and I do think the experience is better for it. The animations do better sell the surprise of getting nothing, and the more spread out text boxes provides a better pacing. While I did prefer the original takeaway in the original ending, as it stands now, my score just reflects personal preference.
Good job.