Just press the space bar or click your mouse to flap the bird. To move upward continuously, you must tap the flight key instead of holding it. Holding the flight key will result in a glide. To start/reset, just click the green flag. I don't have a losing screen yet.
This is an attempt at remaking the game "Flappy Bird" from memory in just a few hours. It's not accurate, but it works. My high score is 217, try to beat that :]