2. You can try to get wrapped up in NaissanceE, but I don't know how substantial you'll find it. The horror is a subdued sense, not an immediate one (at least, not right away). NaissanceE also lacks any clues that push the plot in a specific direction or toward a specific metaphor.
3.Undertale - If you're going to get involved in Undertale, might I recommend you keep all talk about it in the one thread - video games? Just so that others who haven't played it yet won't get spoiled

4. If you want hard puzzles...Antichamber? No horror there though.
5. "Former" most crazy Submachine addict?