This game has serious potential both in terms of story and game play.
I would give you a 10/10 remark because I had a great deal of fun playing it, but this also doubles as a piece of criticism, allow me to explain.
The intended controls has you pressing G to separate, and pressing H to unite, pressing UP makes blue jump, and blue has the ability to double jump. What I found that's probably untended is by uniting then separating mid-air, blue's double jump count is reset, allowing blue to jump one more time. By pressing H, G, and UP in a constant loop, blue can gain infinite height.
Now I did mess up a couple of times, so this can be seen as an optional movement tech, hence the 10/10. However, doing so trivializes the need for red's mechanic, which makes me feel red's game play is underdeveloped.
Now that I think about it, this tech might also recontextualize the story and theme as well. Keep this tech in mind if you decide to continue working on it.