If you want to pass this level, try to avoid the crumbling tiles as much as possible as the Runner. By all means except from dying, keep away from them. This is a major strategy in this level, since all of them are connected, hence taking a single one out will destroy the whole chain. If you can do this, your chances of beating this level will surely increase.
The Child, despite having even less agility than the Skater, will not crumble the crumbling tiles by walking on them, and you can step over a 1-tile gap, hence moving around on the crumbling tile chain will land you back onto the regular tiles.
The Angel has a very flexible jump length, from the regular jump to the dash plus a little glide after the dash ends. Use the dash wisely, and use it as the regular jump begins to lose momentum.
Overall, this level is considerably hard with the wrong characters, but a little thinking and experimenting will get you through to the next level.