The game is incredibly buggy. So you will have to press the flag twice sometimes. Otherwise, it's really simple, you press start and then you jump with "Spacebar", "w" or "up arrow". Hope you enjoyed it! Btw, The start button comes up on the game surface, but I don't know how to fix it so I don't care.
Me My record is 44 My other game: https://scratch.mit.edu/projects/917130520