Really cool concept, I really like the way the tutorial naturally shifts into the first level. The merging sound effect had me positively in tears. I really appreciate the level design also, merging asymmetric and symmetric levels really makes you think and catches you of guard. The only minor critique I have is that maybe it would be nice if the orbs being joined together had some repercussions? I found that stages could easily be completed by simply remaining merged through the entire playthrough.
Very nice job all together though <3