I actually like this idea, I think there is a lot of things you could do with this.
Pro:
1. music is relaxing
2. multiple solutions (I dumb did convoluted way)
3. UI is simple easy to follow
Con/improvements
1. In order to make it more "puzzly" I would remove nodes in later levels once that player has feel for all of them so they are forced to think of a different solution
2. UI could be a little fancier as in more sound effects and a better color palette (less gray and more colorful/brighter colors)
3. I had issues selecting the ports to connect sometimes maybe make the ports bigger
4. Make the lines connect from either way
5. Font should be bigger can be difficult to read
6. If you were to expand on this I would make puzzles that are more then just text