How do I increase difficulty within the same level

For instance - in the Flappy Bird game the columns get closer together and even change angle as the level progresses. In all the game examples and tutorials I have read the difficulty within that level stays the same. Any help much appreciated!!

Take a look to this tutorial:

https://www.scirra.com/tutorials/1019/b ... te-runners

Thanks for replying A0Nasser. That tutorial was really useful. Much appreciated!