You also for parts of it have to make your own. You should use TONS of different codes which can be fairly far over a hundred lines if it is going to be amazing with lots of different slopes. You should try and also do something where you can have ALL the different kinds of slopes with a bunch of different hitTests like so:
if(Key.isDown(Key.RIGHT)){
if(_root.ground.hitTest(_x + 20, _y + 10, true)){
if(!_root.ground.hitTest(_x - 20, _y + 10, true)){
_x += speed;
_y -= speed;
}
}
}
That would work for 45 degree angles because if you have it hitTest the right side at an angle farther out and not on the left, then he goes to the right two and also upwards two. Just be smart about it and use lots of elses and ifs :).