This is level 47 of the Main tunnel.
Using the Runner playing this level is easier. Her running speed and speed of jumping give her a great boost for beating this level. Using the Lizard may making it jump too high and too far, making it easier to land in the gaps. In the level, don't worry about the crumbling tiles, since most of the time when you land, you need to jump again, thus decreasing the fatality of the crumbling tiles. This level is relatively much easier than the other later levels, so cherish it.