I loved this. I wish it would have been a bit longer and a bit more interactive, but it was a solid storytelling experience. The atmosphere was creepy and I couldn't wait to see what would happen next. I don't know why people had a problem with the walking speed. I thought it was appropriate (have you ever seen anyone run on the moon?) and I feel it added to the suspense.
I would love to see a bigger version of this (get your ass on Kickstarter and fund a full-fledged version)!
I'm working on my second playthrough to get the secret medals.
Fun Glitch: If you press both left and right arrow keys at the same time, you can make John "moonwalk". I don't know if this was intentional but if it wasn't, it's eerily fitting.