you can take a staircase, put it vertical and merge a man cannon into it so you can't see the cannon but you still get pushed up, but besides that it's imposable as far as i know.
You can interlock objects at just the right height so you can walk them like stairs, but the angle of the most vertical ramp that you can still walk up is probably the same as the stairs equivalent. Just make a wall with notches so each jump takes you up a "rung".