How to Program Endless Runner/Flappy Game

I know this question has come up once before, but I still couldn’t figure it out. I’m teaching my students how to program games using flowlab. I have a few students that want to make a flappy bird style of game. Instead of making them create an extensively long level, I want them to be able to set a point in the game where it sends them back to the beginning(kind of like the time warp example used to answer a similar question). Can someone explain this to me in layman’s terms? My students and I would greatly appreciate it!