Hi,
At the moment i am working on a 3d Jump n run. it is planed to make 3 diffrent kinds of level a Laboratory, a Tree / forest and a Desert environment.
The Laboratory will be somthing like breaking out at night, the gameplay is slow and difficult.
At the trees you will have the Jump n Run which is easier and faster, as well as a level where you fly to the next tree.
The desert will be the fastest environment, where the player needs to find the fastest way to the destination.
Every environment will get some level (about 5).
If you have any suggestion please let me know 
-siebencorgie