1. "Frostlorn"
Snowy apocalypse; increasingly cold temperatures and eventually perpetual snowstorms force mankind underground where they have must heat every room they live in, in addition to generating oxygen and the like. Dark, with a heavy focus of survival against the elements instead of survival against antagonists. Plot would likely revolve around retrieving something from the surface or exploring ruins on the surface. Not originally my idea, but original creator never did anything with it.

2. "Divided"
Parellel dimensions; two worlds identical in every aspect, but villain begins to create larger and larger differences, sending them both on a crash collision course. Would have the unique mechanic of two versions of every character, with tiny (or large) differences in their backstories affecting their personality and allowing for interesting character moments. Unsure of genre; most likely steampunk or modern.

3. "Black White Red"
Steampunk story of angels and demons; a rebelling god gathers his servants and like-minded demons and collects certain mortals to teach them angelic, demonic, or blood magic, and they attempt to break the stranglehold on power the lead god has.

4. "Caught in time"
Characters wake up trapped and without memory of their history in a massive clockwork building; living conditions are adequate and food is plentiful, but clues are slowly unveiled as towards the building's dark history; contradictory facts pile up, and to escape the characters must find the secret. Freeform exploration with an emphasis on puzzle-solving.

5. "Avatars"
In a fantasy world ruled by a pantheon of gods, a mysterious power has cast them from their thrones, trapping them in their mortal avatars. Now, the gods (PCs) must work as mortals to reclaim their godly power before they are killed permanently--or worse.

6. "The Shadowdancer"
A noble is holding a party, and the crowning event is the auction of a rare and extremely valuable sword. However, when the weapon is stolen from under the very tightest of security, certain persons with vested interests in recovering it must track the thief across the country to get it back.

7. "The Order of the Black"
In a fantasy world, people born with extraordinary powers are sent to join the Order of the Black, an ancient, originally monastic, organization founded by the Church to contain powered people. A supernatural invasion broken by the Order convinces the Church to make them independent, but as the memory of their defense grows fainter priests, kings, and common people alike grow to distrust the Order again. The isolated superhumans must put aside their distaste for normal people to defend them once more when extradimensional forces threaten the continent.

8. "Dreaming Dark"
In a Victorian-esque dystopian society, a strange few have the power to walk through shadows, vanishing to re-appear in another nearby. Some are assassins, some are thieves, and some attempt to ignore their abilities, but regardless of how they use them, they're hunted by Wights--normal humans who have ingested their blood, gaining the ability to track them through shadows and even use a limited form of their abilities. However, neither side is aware of the true reason for the existence of the shades, or the truth veiled within the murky gateways they traverse.

9. "Nameless"
In a post-apocalyptic fantasy world, a white mist has overtaken most of the world. It corrupts animals and plants, twisting them into albino spectres of themselves. Flora becomes reliant on mist instead of sunlight, and becomes larger and predatory, attempting to ensnare and strangle anything that passes within reach. Fauna slowly becomes less physical and more ethereal, giving already dangerous animals vicious intent and the ability to move through the fog undetected. Humans affected by the mist slowly become incorporeal, their minds decaying. Their emotions are slowly numbed, and their personality shifts radically until it fragments and shatters entirely. Eventually, they lose their physical form and become one with the mist. There exists only one civilization untouched by the mist--Nameless, the legendary perfect city. When the Walls of Light protecting the southern civilizations begin to fail, the residents must chart a safe path north to escape to a place generally considered to be a myth. But even if Nameless exists, can the vanguard explorers survive their journey through the mist?

10. "Arcana Machina"
In a futuristic cyberpunk setting, magic has long been able to be harnessed by huge machines, powered by gifted individuals linked to them by invasive networks of cybernetics. It is used for factory lines, war, metahuman enhancement, and other purposes, but the expense, difficulty of transportation, and size of the ACDs (Arcane Chanelling Devices) make the supernatural an impractical resource for many things. However, when a corporation designs ACDs small enough to be portable and used quickly by lone mages, an arms race begins as various organizations try to perfect the technology before a competitor monopolizes it. However, their efforts attract the attention of a powerful otherworldly being, and no one can know what its intent is.