I'm pretty sure what i did was to apply a constant force downwards. As in real life, gravity is constantly affecting everything. :o) If you set your collision mode correctly, you shouldn't have any problems walking up slopes. I also use a linepick to determine whether the player has ground under his feet, so if he walks off a ledge, the fall animation can play and real gravity comes into play, instead of a small downwards force.
The linpick can also be used to stop the player walking up angles that are too steep.
The linpick can also be used to stop the player walking up angles that are too steep.