Development Hell: The sequel. Eternal Darkness is one of Silicon Knights' most well-recieved I Ps, and they've wanted to do a new game for a while. But the GameCube has come and gone, the Wii was on its way out (and, due to the Wii U, is on its way to be obsolete as well), and Too Human was an expensive flop. After the failure of X-Men: Destiny, a prototype for a sequel to Eternal Darkness that never got off of the ground and a lawsuit from Epic Games, things aren't looking any more hopeful.
And the spiritual sequel is faring no better, because it has the unfortunate position of being in a hefty Catch-22 Dilemma. A lot of fans refuse to support it financially because a lot of the original team is not involved, but among those who are is creative lead Denis Dyack who is also causing a lack of support on account of being accused of shady business deals. He can't step down as he was one of the masterminds of Eternal Darkness and is deeply integrated into Precursor's work on SOTE, but he would have to in order to appease the vocal majority.
Executive Meddling: A positive example. The companies attitude towards design and management is and was rather draconian, and it was only due to Nintendo demanding and enforcing a product that was up to the brand name's standards that the game was as good as it is.
Entire sequences of play turn out to be hallucination, reverting to a prior point in play (side note: corridors, doors, windows, and environmental objects will often be located in different places or not at all the second time through these sequences) Usually in conjunction with another effect, including these:
Casting a spell and it causing the player's torso or head to explode, complete with game over music.
The player's head exploding for no reason, complete with game over music and gameplay continuing.
Limbs falling off one at a time.
Entering a room full of tiny monsters
Sinking into the floor.
A room full of monsters that all die and disappear with a single hit.
There are four sanity effects where an image of Edward or, as revealed in the fourth, Pious using his form peers over Alex's shoulder and whispers to her as she's reading the Tome of Eternal Darkness, and while they can be triggered at any point in the game prior to the following points, they will inevitably be triggered at those points if they weren't already, regardless of your sanity level at the time:
1. "I will keep the darkness away." Karim's chapter, just before he gets the Ram Dao.
2. "You've been my little girl..." Edwin's chapter, as he starts going down the second large flight of stairs.
3. "I just wanted you to grow up, to grow up and leave me alone!" Roberto's chapter, after he gets the key to the Forgotten Corridor.
4. "You don't even know your own destiny..." Michael's chapter, a few rooms before his escape from the Forbidden City.