Side Scroller Game

I used my planning documents to design my characters and to plan out my game concept. I was playing to create a game where u are a green cube and u are floating over a dangerous ground and you have to avoid obstacles to get to the end. I was only able to create the gravity so that u fall but u can go up. I wasnt able to create a scrolling script but it was suppose to move but move up and down occasionally for variety.