Should be pressed and held simultaneously, that makes them interlock arms and walk up the yellow pipe's sides. All around Oho Ocean and Gwarhar Lagoon, yellow pipes result in the seabed, while in Teehee Valley, they lead to underground ruins. Other than common Warp Pipes, blocky 8-bit pipes also surface https://vocal.media/art/elevating-craftsmanship-the-charm-of-ceramic-pipes-by-cosmos-art-ceramics