Traumafessions :: Reader Griffin on a Cinematical Children's Book

Hi there kindertrauma! I've sent you guys a question before and I don't know if you have a limit of one question per person, but this question has popped into my head and it's driving me nuts!

Anyway what I'm trying to remember is not a movie or T.V. show, but instead a horror book for kids (and no, it's not a GOOSEBUMPS book), it was a picture book about a boy who goes into an abandoned and haunted movie theater and finds a nice popcorn and soda waiting for him and a movie about to start, so he watches the movie which is an old 1950's era B-movie about alien spiders on Mars and suddenly the kid finds himself IN THE MOVIE!

And what really scared me about the book is that it ends with him trapped in the movie and possibly eaten by the spiders.

I'm pretty sure it had "Spiders from Mars" or "Mars Spiders" somewhere in the title, but anything I Google gets me nothing but DAVID BOWIE results. Oh, and in case it helps, I believe the book is from the late ‘90s.

So there you have it, this has been driving me nuts and of course I no longer have the book anywhere, that would be too easy, so here's hoping you guys can help me out!