I know that what I'm about to say probably isn't what developers thought, but heres my perpective on this game.
I think that all of this is just symbolism. We are the aliens, each with our own talents. The tunnels respresent our lives on Earth, and the end of the tunnel is the future. Everyone goes through life, makes discoveries, and goes toward the future. And when we think theres no more left to discover (Say, getting stuck on a level), someone proves us wrong (You pass the level), and we continue on our journey. When one of us does something wrong or are a bit too curious (Going down a subroute) we are eventually met by a dead end (finishing the subroute) and go back on track. Eventually, we will always create problems and inventions (Player-made levels) and we will fix the problems and find uses for an invention (Finishing a Player-made Level) keep on going!
Anyways, thats how I think of this game, 5/5