Version 1.9 is now in the source files folder. It was time for the enemies and the player to interact, so I have now added the code for collisions.
When you hit an enemy, if you are higher than the enemy, they die. If they are higher than you, you die. If you're at roughly the same altitude, you bounce off each other. Eventually, a dying enemy will turn into an egg that must be caught before it hatches into another enemy. At the moment you just disappear.
I have also added a God mode, to make testing easier. Press G to turn it on. When god is active, you cannot die. Also, you can prevent the enemies flapping by holding down 1. Take that, birdies!