Press D to see list of dragons. Press fight to fight another dragon and earn money. Press the buy button to buy a new dragon if you have enough money. After you press D, press 1, 2, or 3 to swap dragons, do the same thing when you start a fight. When fighting put the mouse on the attack button in the bottom left corner and press space to change attacks.
Thanks to @Josh_Clickbait for the music, Note Flight.
