This is level 3 of the A-Tunnel.
This level is nearly all crumbling tiles. And you have to jump across platforms, and move around to different sides of the level, making it slightly difficult. Inexperienced players may take a while to beat this level.
The Child is useful in this level, as he can run on the crumbling tiles without crumbling them, and his jump can be far enough to float a long way, so you just need to take care for landing. If you see yourself going to jump into a gap, try to land immediately by moving left/right and touch the platforms on the wall, and this can be useful. Since all the crumbling tiles are apart, you can jump without any consequence, fortunately.
As for the Bunny, you can try to rush past this level by letting the Bunny keep bouncing, then jump a huge jump and cruise through a large portion of the level.
The Runner is an all-rounder for most levels, so you can handle this level fine with her if you have enough skills. Just do high jumps and look for a landing place.