It's difficult to review this kind of game. Art games, as it were, are a niche that have a lot going for and against them at the same time.
As people have mentioned, the gameplay was lacking - what carries the game is the consistent gritty quality, the incredibly novel mix of pixel graphics with detailed textures, and the sense of longing that the main character has, for identity, for closure, for companionship, for escape. The fact that I've gotten all of that really is a testament to your ability as an artist.
But you need gameplay. You need something beyond artistry. As you know, there are many games with great graphics, jaw-droppingly beautiful scenes, spine-tingling music, etc etc that fall flat on the actual reason most games are sought out: the entertainment value. My recommendation is to research game mechanics, or to work with someone else, allowing your creative process to fuel the flavor of the game and the mood, but allowing them to sketch out how the game will actually function.
"Swimming through the sky" and "using mirrors" for example were great ideas, but could be fleshed out so much more than what you did. Now I realize a collaboration for this particular game would have been a bit grating, as it is so intensely personal. I do hope for future projects and career decisions you'll consider what I've said though.
You're a beautiful artist. And given the lack of glitches and smooth gameplay, probably a good programmer as well. However, when it comes to execution of your vision, I must say with all due respect that you fall short. I think another review said it too: with a great concept comes great expectations, and the actual game doesn't live up to the environment it is set in. It's like a slower, early form of Mario Bros set in the lush storyline and graphics of Final Fantasy X. There's a disconnect.