The main strategy here is to abuse the Whirlpool Pipe. If you press Up after bouncing on Mudkip, you can cut your upward momentum so that you can drill down sooner for faster hits. One strategy is to simply mash up and down. What I do here is try to stick with a certain rhythm while also trying to stay atop the robot. I also almost died at the end because I wasn't expecting a one-shot on the second phase and attempted a quick second hit.