Fantastic entry! I really enjoyed something weird but not threatening all life as we know it.
Teenagers entering the abandoned amusement park? It's believable but I immediately thought of Scooby Doo. It won't make or break this article, but I'd recommend changing that to something else, such as real estate developers or amateur local historians.
How do we know that erasing Jack's facial features will ruin its ability to speak and whatnot? Did some doctor try that?
In my opinion, Addendum 3 could be cut and you wouldn't lose a thing. It seems a bit out of place and purposeless. It's kinda funny, don't get me wrong, but it's not hilarious either.
That's all I can recommend. Great work here!