Have Enemy Follow Floor?

Is there any tutorials I'm missing that suggest how to have your AI enemies follow a slop in a floor I have a decline in my floor and when I have my enemy set to a bullet behavior to have him move he just flies across the screen in a straight line... thanks all

I have him following the floor now by settle his angle after hitting a certain check point.... however I have him moon walking upwards after hitting another check point that is suppose to invert all this and have him climb back up the hill instead he moon walks into the air and the opposite direction... I was setting the angle of the image and the angle of motion on the bullet effect....