Well, to be honest Slender: The arrival is pretty interesting looking. It's from the creator of the original Slender game, but it's not that collect 10 pages for 15 minutes and that's it. It's supposed to be a full-length story driven game.
Slenderman is pretty tired, but if you put some good effort into it and make something creative, then it can be good and interesting. But your setup does sound cool and could work with other monsters too. I hope the actual game has more to it than collecting pages though, as that isn't very interesting after the 100th time.
I would change the title to avoid confusion with Slenderman's Shadow, especially when that game caught on very well.