help needed

i am making a parkour game and i want to make it so you have a health bar and if you fall off somthing too high and dont press a button you lose health

Link?

http://www.flowlab.io/game/play/119901

You already have it.
By the way, ACTUALLY USE SOME GOD DAMN TEXTURES

by the way if i added texture it would look like someone smeard two shits on the screen

How does this work