The Porthole puzzle is the manipulation of colored portals in order to deliver a ball from the left pipe to the right one. There is free space between them and you can move using special portals. To do this, they need to be deployed in such a way that the ball slips through and jumps right into the adjacent pipe. Portals of different colors are not combined, you must first move the ball through the same passages, and then move to others. Sometimes there will be more portals than needed, it is not necessary to use everything in the Porthole.
