How about a map which is divided in two worlds. Kinda like ctf-catherine for UT.
But this time you don't have to fly through tubes to reach the other side.
This time you jump in.. for example.. a pool, swim down, and when you surface you're on the other side. But up there is the sky, and you'll have to get out of the water again get the idea...
It's as if the world, or you, turned around during your swim to the other side, but you weren't aware of it.
Maybe combat in a human body. Like that Q3 level, open sore. Was a good idea.
I've probably mentioned it already, but combat in a city like the one from "the empire strikes back", the one named "cloud city". Would be nice. There's this huge depth beneath you. But there's no immediate danger of you falling down. You just need to watch your step. A little.
A house level. BUT, there are many hidden (open, secluded) areas. For example, you can open the closet and there's this loooooooong corridor. Filled with say... blue-ish light, and cobwebs. And maybe some skeletons jammed in the walls. Some spooky sounds.
The bath tub is filled with water. It's so dark, you can't see what lies beneath. You grab a rebreather and jump in. ONCE you're down there, the water is "crystal clear". It's so pure, it almost blinds you. There are also well, f.e. crystals down there, and maybe maybe some sort of light sharks.. big fish no idea. Maybe keep them as props, extras.
The yard is a trap. Once you go outside, you see a small yard. The lawn is mowed. There are some bushes all around the garden.
BUT, once you step on the grass, you become quite small. STILL big enough to maintain a certain sense of orientation. It would kinda suck if you'd be so small the grass would be as big as trees. You could go wander around forever before you could find someone.
A space station, but for civilians. There are for example malls, there are living quarters tralala you get the idea. But it's been raided by space pirates. And almost destroyed, from within. It's been floating in space for some decades, and eh... Liandri found it and used it a special deathmatch level.
For those who want stealth combat. Or maybe, they plan on using certain areas for tourneys. Dark areas, no sounds, rubble everywhere.
Maybe for darkmatch games (mutator material).
Maybe a downhill speedmatch. You jump on a hoverbat, turbo sled, whatever and start racing downhill. Say f.e. it's centered around the sunspire.
But, the area's been covered in snow (imagine the scene from spirevillage. This was actually a HUGE level, and it included the spire).
There are obstacles in your path, like skaarj (or krall for that matter) jumping at you, nali you have to avoid. If you run over a nali, they explode redeemer style etc...
And you have to start all over again hehe.
What about combat in a T.v.
You're caught in tv world. One moment you're fighting it out in a western movie, the next you're running around on a football field, tennis court and before you know it you're in the news. Fighting around a battle field in some country...
Etc