This is level 45 of the Main tunnel.
When you use the Runner, do short hops between the rectangular platforms and run forwards till reaching the edge. Then jump high and look for another landing spot on another platforms. Repeat and reach for the end. If you choose to use the Lizard, you can do high jumps and try to stay in midair throughout the level. If there aren't any tiles in front of you, use the high jumps and try to land on a platform on the wall, next to you. But this requires changing gravity in midair which is quite risky. So good luck!