This is level 7 of the G-Tunnel.
It's really fun to use the Child in this level, because there are huge platforms made of crumbling tiles and lots of ramps which you should jump off. He is by far the best character for this level.
If you haven't beaten the Low-power Tunnel, you can try the Runner, but this is significantly harder. Follow all the yellow tiles to the finish. However, this is easier said than done, especially near the end, where there is the ramp equivalent of mogul skiing. So rather than using the Runner, try beating Low-power Tunnel and unlocking the Child.