Truth or Dare looks...alright I guess? The director did some decent horror movies like Cry_Wolf and some episodes of Bates Motel, and while I guess the trailer wasn't the most amazing thing in the world, I have to admit that pool table neck snap got to me. Biggest problem for me is that it looks like its taking its (stupid-as-hell) premise waaaay too seriously. Still, Happy Death Day was surprisingly decent, so I'll see how it goes.
In terms of maze content, though... I mean, I can see bits and pieces of a decent section in there. The grinning old woman in the hospital, the mirror scene (can never forget the mirror scenes!), the old man in the dorm room, the pool tables, the library filled with crazy people, plus whatever the finale's gonna be... throw in a few concrete alleyways with "Truth or Dare?" written on them and bam, instant Blumhouse section.
Now, I'd prefer it if Blumhouse let the field lie fallow for just a few more years, but if they wanna do it, it's not an instant disaster.
EDIT: Slender man, I guess I'm keeping an open mind. Just from what we've seen, a Slender house will be a little short: a few Friday the 13th woods sections, some stilt walkers, an asylum section, attic filled with pages. Maybe those flashing black-and-white images could make an awesome finale somehow, I dunno. Something about the trailers just felt a little off, but I guess I'll still give it a chance.