To beat this level, time your jumps with the platforms by taking short, or long jumps. This is a somewhat hard level, but simply follow the path and instinct will get you to the finish. Beware of hitting the front of a platform and bouncing, this slows down your speed and can catch you off guard.
To get the bonus, start by going to the lower platform and change gravity by going right. The rest of the level should be like the gameplay above, but once you get to the end, time your jump on getting the bonus and land on the ending platform. Jump too early and you won't get the bonus.