Let me explain this. Start like with the pencil wars. The arrows you see in the first part are a fast way to cross. The rule is that if you stay there you will be destroyed and then you have to restart from the beggining. The “checkpoint” lines were drawn there so if you pass it, and then you loose, you restart there. You will see another lines, these are the “tusken raider” area. The same as with the fast way. The first one to finish has the right to choose the ship they want! Vader’s tie or milennium falcon. Have fun!