Having a pre-made adventure means that a GM doesn't have to spend so much time coming up with ideas whole-cloth. But they can also sometimes feel constraining. The Adventure Kits from Absolute Tabletop are a bit more freeform than your standard adventure. They've got a new one, Shadows Over Driftchapel, up on Kickstarter now.
From the campaign:
Adventure Kit: Shadows Over Driftchapel, takes place in the world of Gloam, a near-apocalyptic, Victorian/Colonial-inspired fantasy realm brimming with black powder and shadowy horrors beyond human reckoning. As the end of all things approaches, the humans of the Five Dominions cower behind the walls of their dwindling cities, clinging to vile gods twisted by the creeping darkness of the Gloam. Meanwhile, scarce tribes of elves and dwarves, corrupted by the shadows, eke out a savage survival in twilit forests and crumbling caverns.
Now, foolhardy men and women, wielding misplaced bravery and trusty flintlocks, venture beyond the crumbling walls of their cities on horseback or aboard dirigibles, seeking fortune and redemption across a cursed, gaslit landscape. Humanity rules over a doomed world – but time is running out.
Inspired by the works of H.P. Lovecraft and Robert E. Howard, Shadows Over Driftchapel provides you with everything you need to undertake grisly adventures in a pulpy, horrific fantasy setting.
The campaign's making its way to 3x funded with 31 days left to go.