Yeah, I was wondering about this when I was playing through Gall Spaceport - it was
really infuriating trying to work around this. There was at least one challenge point where I died every time I tried to get it. Shame you don't get the jetpack until after the worst of the slopes, since once you have it you can at least save yourself if you end up slipping off. N64 version definitely didn't have this issue, that much I know.
Returning to a couple of years old post as I just came to see if there is a fix to this.
I played this game earlier only on N64 and there was definitely not this kind of problem there. Never thought that the Boba Fett level was difficult before, but in this PC version it seems almost unplayable, almost as if it was an ice planet.
Visually this game does look stunning and fast in comparison to the N64 version. Too bad that the controls without the pad are kind of bad.