Introduction
This is Level 61 of the Main Tunnel.
Suggested Characters: 
Gameplay
Take note that after the Main Tunnel and the Winter Games, it would be a good idea to get the Child. Many levels can be passed with less work, and some can be completely bypassed without pressing any buttons, like Level A-4, because he can stop crumbling tiles from falling.
As the Runner, don't be afraid to drop a little on the crumbling tiles, or you may not land on the next platform. The possibility of overshooting is there as well for the smaller platforms and tiles, and stick close to a wall as you jump to avoid this.
You could also just keep jumping as the Skater, but remember you can shorten jumps by hitting a wall mid-jump. He goes fast, but here if you sink into empty space you will have a little more difficulty getting back into the tunnel since he has a low jump height.
Or if you've taken the challenge and beaten the Low-Power Tunnel and obtained the Child, you could just jump in the middle of your current platform to reach the next one. Don't jump at the end or you might overshoot, and since there are a lot of sides, it's not easy to stop the jump.
Walkthrough
Level 61 Walkthrough (Run 3)