Pretty basic. Use the up arrow, W or space to go up and the down arrow or S to go down. Collect as many coins as you can as you get faster and don't touch the lava!
Psssssssst! I've included a block in the Neon Scratchy Sprite that makes it go black and white! It's a loose block which isn't attached to anything, so it's pretty easy to see. Use it in some of your own projects!