I only had a short time to skim through it, but at first glance it looks enjoyable and highly readable. I'll try and get back to it later this weekend.
In the meantime, one thing you may wish to consider is deleting the very first line. Open the story from the second paragraph, the one that begins 'Yesterday was Jake’s tenth birthday...' It's a good paragraph, and you won't be losing anything that you can't slip in later.