Click the green flag. Press space so that you can make the butterfly move from your path and make it easier to reach the end, and use the arrow keys to move through the cave and reach the end. If you touch the butterfly, you won't lose, you'll just lose points. If you touch the gray borders, you will automatically lose the game and it will show the dragon exploding. This is a more challenging game to code & play. Things you can change: 1)Sprites 2) Colors 3) You lose 4) Music 5) Backdrop (Make it sort of like this backdrop we have in this game)
Docs: http://bit.ly/1KEakrf (SHORTENED LINK)