Kai Dracon
Writing a dinosaur space opera symphony
Personally, I'd reboot the whole thing focusing on the lovecraftian angle. Reference the title, "Quake", by having the entire gothic world feel alive and malevolent. Make the world literally quake with earthquakes constantly, stretch, groan, and moan.
Then have it that when you get to the final boss, it is a mountain sized god with tattoos all over its body that look like a maze. You bring it down from a distance, then the only way to proceed is to walk towards it. You end up walking towards it for a longer time than you'd think due to a trick of perspective. Get to one of its feet, see a door embedded, go inside, and you're back in the entry hall of the first level in the game. The entire game world, naturally, being the maze that's built into the god's body.
Then you start over new game+ style with a higher difficulty, etc. And it never ends.
There's your dark and evil Quake.
Then have it that when you get to the final boss, it is a mountain sized god with tattoos all over its body that look like a maze. You bring it down from a distance, then the only way to proceed is to walk towards it. You end up walking towards it for a longer time than you'd think due to a trick of perspective. Get to one of its feet, see a door embedded, go inside, and you're back in the entry hall of the first level in the game. The entire game world, naturally, being the maze that's built into the god's body.
Then you start over new game+ style with a higher difficulty, etc. And it never ends.
There's your dark and evil Quake.