Plot
Demons are trying to invade Heaven and have built a skyscrapper to reach Heaven and conquer it. And they did it right in your backyard! So you must ride 30 floor tall building all the way up to the roof to stop them.
Hellevator
Hellevator is speedmapping community project built around time and space limitations. Each map was built in 3 days with only small balance, textures and bugfix adjustment allowed afterwards.