Use the left and right arrow keys to turn. Jump over the obstacles using the spacebar. Watch the size of the heart in the corner - it's your "health", or stamina. You lose it over time, and will have to collect the treats you find along the path to recover it! Be careful about tripping over the obstacles, they will make you lose stamina too. Follow the quests by clearing jumps, collecting the special quest items, and delivering items by holding the down arrow when you're next to the object's destination.
If the internet is busy, I recommend not playing in fullscreen. The bird call sounds are from SoundBible, but every other sound and image is made by me. Have fun!