Move with WASD. Don't press space after Chick has already told you to and you have pressed it once. I highly recommend you read all the dialogue bubbles and don't move while Chick is talking/thinking/think-talking. When in doubt, to the seeds!
I used the book Coding Projects in Scratch to make the snow at the beginning but the rest is all original (besides a few very helpful websites and Scratch discussions). I recognize that this is not very good, but it is the first time I ever attempted a "platformer" of any kind. I recommend checking out the sequel, Chick's Second Adventure!