One really cool thing about platformer games are their physics-based obstacles. This would mean items such as teeter-totters, items that crumble, items that swing, and so on. Let's start with a basic pile of rocks with a ramp on it. Start by creating a new scene and copying our beginning ground block into it, as done before. Also, let's name this scene Rock Jump; duplicate an additional eight ground-blocks (so there's nine in total), and extend our scene bracket to match the length of the eight ground-blocks. You should have something like the following screenshot:
Now, remove the fifth and sixth block from the left to create a two-block gap just right of center. We duplicate the blocks all the way across the scene to make sure we have a level layer (rather than dragging and dropping across a gap). It's just a quicker way of doing things, but if you like, the same could be accomplished by dragging the fifth block over, and then continuing the duplication. Your exact process...