Example video:

Run forward as the level loads. Stand on the corner of the platform so that it tilts and you can use it as a ramp. Jump across the platforms to the 2nd moving platform. Jump (Don't butt bounce) to the corner of the grassy platform. next, jump up to the corner between the grass and the path, and when pac-mans arms are at their highest, butt bounce again. This should make it possible to do this ledge-grabless. Aim along the left corner of the path, it gives you more height than the right corner. Aim and roll so that pacman is facing towards the left corner of the button. Next is the hardest part. Just make sure that pac-man is completely against the button and that his right fist stays in the light green section of the button and that gives you the optimal angle to roll at. It's tricky to set up on the fly, but you get a feel for it eventually. Now just climb up, and rev roll across the two pits. If you get hit by the ghost right at the end, that's good, as you'll maintain your rev roll momentum while the hurt animation plays. Stand on the top of the ramp and rev roll to the end.