I can get to the part where it is grassy, after you have entered the tunnel by ducking with down arrow. The problem i, I can't get past the grass, or if it is a ramp made of grass how do you use it. It said to duck for that tunnel thing (or half piep) but you use the down arrow, not the B button... after that there is a patch of grass in a U shape that you have to dodge.. how do you do it.