Introduction
This is Level 64 of the Main Tunnel in Run 3.
Suggested Characters: 
Gameplay
All the walls and platforms placed high up mean a high-jumping character is required.
Always be ready to long jump as the Runner. This level is a test of reactions and judgement. Don't drop too low on the crumbling tiles, but don't jump the second you make contact with the crumbling tiles either, since you'll most likely undershoot.
Alternately, you could use the Bunny, allowing you to make progress very, very fast indeed. The Bunny moves fast and jumps high, which makes it sort of unpredictable to some degree. Use long bounces sparingly, only pulling them out when you have to.
That should get you to the end of this level, and to Level 65, the last level of the Main Tunnel! Woo-hoo! Hang in there. Nearly at the end of the Main Tunnel! But this is the penultimate level. The next one's hard.
Walkthrough
Level 64 Walkthrough (Run 3)