One of the ideas that I originally wanted to implement in Uber Arena, but halted progress on due to technical limitations / roadblocks (mainly with getting mouse controls to work correctly with angle changes, and I think some of it is buried in the engine source code rather than the Q3 game code), was the idea of directional gravity.

At its most basic, directional gravity would be stuff like walking on walls and ceilings, with items also being located along these planes. But the idea can also be expanded to work with any angle in any direction, allowing for smooth transitions. So you could have a smooth ramp from the floor to the wall, and likewise another from the wall to the ceiling.

To prevent breaking maps, directional gravity would only be enabled on specific surfaces. To allow for strafe jumping the player could "float" a certain distance away from the surface normal, but after a certain distance would "detach" from the gravity field and return to normal gravity. Though that's just one possible idea and maybe there's a better way to handle that.

This idea is pretty simple but would undeniably add a lot of possibilities to level design for arena FPS, much like trampolines, which are in fact implemented in Uber Arena.

The 2006 Prey game is a good example of a game that has tackled antigravity surfaces like this. Portal 2 also initially planned to have a purple gel called the Adhesion Gel which would have this same property, though it was scrapped because it allegedly made playtesters sick.

That whole sickness thing might be a potential roadblock, though who knows how Valve implemented their version of it. Perhaps there is some way that antigravity surfaces could be integrated into arena FPS while ensuring that players don't get sick using them. Ideally, strafe jumping across directional gravity ramps would, if implemented properly, be just as natural as strafe jumping across a flat surface. The transitions should be silky-smooth.

What do you, the players, think?