Hit the wall with the roundabout on the edge of the altar and smash an organ there. There is also a roundabout behind the organ. Then put these two cycles back to the altar. There is also a roundabout on the other side of the map. Go back to the altar, then make four loops and enter four purple apertures, and you can continue. I remember that a door that could not be opened would be opened. The landing point around the island does not need to be very accurate, as long as it is close to the purple aperture, it will be sucked in.