This is a single-player/multi-player map at which you are stuck on a tropical oasis in the middle of the desert where you must survive! You start out with one tree at which you must replant, and survive before nighttime comes. Sugar Cane can also be found in a secret alcove in the lake at the oasis.
Copy the zipped map file *as is* into your Saves folder. The next time you run Minecraft, the map will appear under your Saved Games.