YT+1_8 SlimeChallenge.zip is a release file of the Minecraft map Youtubers+ SlimeBlock Rolercoaster, made for Minecraft 1.8. It was published on July 8, 2015 and is 11.2 MB in size. For the full description, screenshots and every other version, visit the Youtubers+ SlimeBlock Rolercoaster map page.
How to install: Extract the .zip and move the world folder into .minecraft/saves; the map then appears in your Singleplayer list.