This is the 2nd bonus level played by the Runner. You can unlock it by collecting 10 bonuses.
This level shouldn't be too hard if you know what you are doing. You need to carefully jump between platforms, catching on the sides whenever required.
To collect the bonus, you need to:catch onto the underside of the first platform, then you need to catch onto the side of the right platform, moving to the left, catching onto the left side of the platform above you. Then jump onto the bonus and then jump to the finish normally.