Using Physics To Move

I am trying to make a character that moves like the are slipping on ice constantly. The idea is that players skate around and gain speed going down hills and slow down going up hills and moving with terrain and the likes. Basically, I want something similar to the movement in this vid: Halo 2 Without Friction - YouTube .

I tried simulate physics on a character and I got the sliding, but gravity basically does nothing. After awhile of testing, and adding a physics material to the capsule component, I got gravity to affect movement, but then I couldn’t control the character at all. It was like all inputs just stopped working entirely. On top of that, looking with the mouse was crazy, the character would rotate slightly and then suddenly a ton, freaking the camera out.