I just had a thought about a block that when holding a certain button, you could go up them and when not holding it, you can walk through it.
I'm not exactly sure what your trying to suggest, can you elaborate? or re-phrase? You can walk up/down 1 block transitions if you didn't know so any blocks can be used as stairs.
He means that you can walk through the blocks but when a button (say space) is pressed it allows you to walk up that block
Well there appears to be stairs in the game already. Hence this image: http://i.imgur.com/sMJBN.png So I would assume there is a way to go up and down those stairs, but i'm not sure if it involves a button to be pressed to ascend. The stairs shown look to be one single dynamic object, but I could be wrong. Since one set of stairs is longer then the other it could be individual "stair blocks" placed. I could be wrong and that whole building is a single placed entity.