just fake it by adding motion to your player in the events that you want them to fall…
All that the gravity is in the game engine is a constant -z 9.8 force that is applied to everything. so to neutralize gravity add a +z 9.8 force to your object. This will make it like it is floating in Neutral buoyancy in water.
If you want someting to just stop in mid air, do a very small value to the Vlin +z .001.
Unlike the force method above, this object will not move when you touch it… it will be like it is nailed to the wall or something rather than floating in water. Although it will rotate… you can use a IPO animation to prevent rotating.
To make things fall faster use a -Z force on your object… this will make it fall faster.
YOu can also tweak the Mass settings to make things fall faster, but that gets complicated really quick… things with lots of mass do not play well with things with little mass, and you will get things floating and falling thru each other.
In the world propertys we have place to tweak the gravity too… we have been advised by Erwin (the guy who made the physics engine) to not play with this setting.