Press the space bar to jump over rocks. If you hit a rock, you get a strike. If you get 3 strikes, the game ends. Your number of strikes is shown at the top left corner of the screen along with the number of seconds you've gone without getting 3 strikes. I suggest jumping right before the rock touches the goat's feet. Heart, star, and follow or a wild goat will smash your computer.
I used the running unicorn scratch sprite and turned it into a goat, because I love goats! But I made the backdrop and the rock myself.