A slope is read as gradual change — up as effort, down as ease or loss of control. How steady you feel on it is taken as the core of the dream.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.